Tag Archive for 'dynamic languages'

JSConf 2012

This year JSConf was in Scottsdale Arizona, which provided some welcome relief from the cold, wet, Seattle winter/spring.

News

One of the biggest pieces of news was that Mozilla gave all attendees a Nexus S smartphone running a developer version of the Boot to Gecko (B2G) phone operating system. When I say developer, I mean, camera support was broken, things were crashing, that sort of thing. These phones were a big hit among the attendees. They contributed to knocking the conference wifi out temporarily, and I saw several groups of people who were working on projects for the phone. My experience at Google I/O had soured me on the idea of giving away free devices. In the case of Google I/O, device giveaways have become an expectation, and there is some proportion of people who sign up for that conference based on the hope of getting a free device. Still, Mozilla is going to need all the help that they can get, and people seemed to take the challenge to heart. I did find it interesting that the Mozilla folks were speaking of B2G as a great feature phone software stack. This is a realistic way of climbing up the stairs in the mobile phone market. It’s hard to imagine a real competitor to iOS and Android, but I’m glad to see an effort in this direction. There’s WebOS, Windows Phone 7, and B2G all using some variant of the open web stack. It seems like there ought to be some collaboration between B2G and WebOS’s Enyo framework.

Talks

There were a bunch of talks on the internals of Javascript Virtual Machines. From a computer science point of view, these talks are interesting. I heard a lot of these kinds of talks at PyCon and during my days at Sun. It seemed that most of the audience appreciated this material, so the selections were good. The part of this that I found disturbing is wrapped up in one of the questions, which was basically, how can we write our code to take advantage of how the VM works. Given the number of VM’s that Javascript code might execute on, this seems like a path fraught with peril.

Also on the language front, there was more representation from functional programming. There was a talk on Roy, and David Nolen gave a talk that was billed as being about Clojurescript, but was really more about having a sense of play regarding all this technical work. Closely related to the functional programming was GPU programming. Jarred Nichols talked about implementing a Javascript interpreter in OpenCL. Stephan Herhut from Intel talked about the RiverTrail parallel extensions to Javascript which do data parallel computing using operations taken from functional programming. The extensions compile to OpenCL, which I found interesting. I wonder how many more languages we’ll see compiling to OpenCL or partially compiling to OpenCL.

Paul Irish did a nice presentation on tools which gave a great overview of the state of the practice in the various areas related to web application development. There were several tools that I didn’t know about. The presentation is all HTML5 but has some very nice visuals and animation. I’d love to know the name of the package that he used.

Ever since Node.js came out, I’ve been enamored of the idea that you could share/move some amount of code back and forth between the client and the server, much as code used to move back in the days of NeWS. Yahoo’s Mojito is an investigation in this space. It relies heavily on YUI, which I haven’t used. I’m looking forward to looking into the code and seeing how it all fits together.

The team at Bitovi make a special lunchtime presentation about CanJS, which is another MVC framework for Javascript. CanJS is in the same space as backbone, knockout, and so forth. It’s claims to fame are reduction of certain kinds of memory leaks, size, and speed. From the benchmark slides it seems worth a look.

Keynotes

Dan Ingalls delivered the closing keynote on the first day. I met Dan briefly when I worked at Sun, and I was familiar with his work on the Lively Kernel. The Lively Kernel is the answer to the question “what if we tried to build Squeak Smalltalk in Javascript”. It is much more than a language, it is an environment for building programs and simulations. I’m of two minds about this work. On the one hand, there’s depression that we still haven’t managed to catch up to the work that Ingalls and his contemporaries pioneered 30 years ago, and that today’s practitioners are completely oblivious to this work (a comment on Twitter confused Lively with an advanced version of the NeXT Interface Builder — the causality is reversed). On the other hand, although the Lively Kernel is written in Javascript and runs in a browser, it’s not really connected to today’s world, and so it’s applicability to solving web problems is limited. Nonetheless, Ingalls received a well deserved standing ovation. He is among the pioneers of our field, and as his generation is starting to pass on, it feels good to be able to personally honor them for their contributions to the field.

I have no idea how Chris Williams convinced Rick Falkvinge, the founder of the first (Swedish) Pirate Party to come and speak at JSConf. The topic of his talk was the politics of the net generation. Falkvinge told the story of how he came to found the Pirate party in Sweden, and described the success that the party is having in Europe. He claimed that about every 40 years, we have a new key idea. Apparently the theme for the period which is now ending was sustainability, and the claim is that the theme for the next 40 years will be free speech and openness. He credits this theme with the rise of the various Pirate parties in Europe, pointing to the European protests around ACTA and the US protest around SOPA as additional corroborating evidence. Falkvinge claims that the Pirate party has widened the scope of politics and given young people a way to vote for the issues that they care about. I wish that something similar was happening in American politics.

Hallway

As always, JSConf had a rich hallway/party track. I had lots of great conversations with people on topics including the Javascript API’s for Windows 8, the mismatch between many concurrency models and real shared memory hardware, and proper use and optimization of CSS. I think that facilitating the hallway track is one of the areas where JSConf excels. The venues are always nice, and this year there were hallway conversations, in pools, around campfires, as well as the usual hotel lobbies and restaraunts/bars/lounges. I was also happy to be able to introduce Matthew Podwysocki, who has been doing excellent work on RX.js, and David Nolen, who has been working on Clojurescript. I think that there can be some nice synergy between these two projects, and I’m eager to see if they agree.

The best roundup of JSConf coverage appears to be on Lanyrd.

Clojure Conj 2011

Last week I was in Raleigh, attending the second Clojure/Conj. The last time that I attended a Lisp conference was the 1986 ACM Conference on Lisp and Functional Programming. I am a Lisp guy. I took the famed “Structure and Interpretation of Computer Programs” course from Sussman and Abelson. I spent some time doing undergraduate research on Symbolics Lisp Machines. When Apple invested some energy into Dylan, I hoped that I’d be able to use a Lisp on a personal computer. Java pretty much ruined that. Over the years, I pretty much gave up on the idea of being able to use Lisp for my day to day work. So much so, that when I first heard Rich Hickey talk about Clojure, my reaction going in was unenthusiastic. By the end of Rich’s talk, he had my attention. Clojure has been doing some growing up since then, and I really wanted to attend last year’s Clojure/Conj, but wasn’t able to.

Almost all of my conversations at the conference involved the questions, “Why are you at Clojure/Conj” and “How did you get interested in Clojure”. I’ve answered the second question in the previous paragraph. The question of “why” boils down to three themes: Clojure itself, Data, and Clojurescript. I’m going to use these threes theme to report on the conference talks.

Clojure itself
Clojure is a Lisp dialect that runs on the JVM and has great interoperability with existing Java code. It has great support for functional programming, as well as several innovative features for dealing with concurrency.

Stuart Sierra started off with a talk that pointed out areas where people could learn beyond the books and online exercises that are available. In each of those areas, he also proposed projects that people could work on. One of the things that stood out for me was his use of the Clojure reader to deal with Java Resources. I always found Resources to be annoying, and the use of the Reader is a clever way to make them more palatable and useful.

Clojail is a system for executing Clojure code in a sandbox. The system is quite flexible and the applications aren’t just limited to security. I can imagine using clojail to implement something like the Sponsors described in the original Actor model. Anthony Grimes, one of the committers for clojail gave the presentation. He is 17 years old.

One thing that made me happy was to see the bridge building between the Scala and Clojure communities. Phil Bagwell, who pioneered many of the persistent data structures in Clojure is now at Typesafe, the Scala company. He came and gave a nice talk about Scala’s parallel collection classes. Perhaps these classes will one day find their way into Clojure Daniel Spiewak gave a very solid presentation on the computer science behind the persistent data structures in Clojure.

At many conferences a talk like Clojure on Android would be at the higher end. The technical level of the talks at the Conj was high enough to make the task of getting Clojure on Android seem mundane. This is to take nothing away from the very impressive work that has been done. There are some issues remaining like footprint and startup time, but it looks like some effort is going to happen at the Clojure core team level to make some of this possible. The thought of talking to a REPL running on a phone, or tablet is a tasty one.

Rich Hickey’s keynote reminded me very much of a Guido keynote at PyCon: a discussion of language issues that he was looking at, and a solicitation for discussion. Rich was very careful to say that the stuff he was discussing was not a roadmap, so I’ll repeat that disclaimer. Here are some of the items that stood out to me. Plans to allow multiple builds of Clojure – a regular version, a leaner deployment version, a really lean Android version, a super deluxe development/debugging version and so on. There is discussion about allowing the reader to be extensible, in order to allow new data types to be round tripped. I didn’t follow the history of ClojureScript, so it was useful to see that Rich is pretty committed to this idea, and that bits of technology might even be flowing “backward” from the ClojureScript compiler into Clojure on the JVM. I was also very interested on Rich’s view that the use of a logic system like that in core.logic would be a far better tool than a traditional type system. More on the logic system below.

The last talk of the conference was Sam Aaron’s talk on Overtone, which is a computer music system written in Clojure. The major point was that he used Clojure to define a language for describing computer music, much in the sam way that sheet music describes regular music. There was lots of cool music along the way, including a pretty good simulation of the sound portion of the THX commercial that often plays before movies. The description of that commercial fit in a single projected screen of code.

Data

One thing that I’ve been looking at recently is exploratory environments for working with “federated” data. I’ve grown to dislike the term Big Data, because it’s come to mean almost nothing, however, the ship has already sailed on that one. Most people would be familiar with the idea of sitting down in front of their relational database SQL command prompts, and issuing ad-hoc queries. As the use of varied kinds of storage systems grows, we are losing that kind of interactive relationship with data. Some of the people in the Clojure community have built some interesting data systems, and Clojure is itself amenable to exploratory work with data, between it’s orientation around functional programming, and a development style oriented around a REPL.

David McNeil talked about Revelytix’s federated (among RDBMS and RDF triple store) SPARQL query engine. Their system uses s-expressions to represents the nodes in a graph of stream processing nodes. These expressions are then compiled down to a form that can be executed in parallel using the Java Fork/Join framework. The operators in the s-expessions are mirrors of built in Clojure sequence functions, and can use and be used in Clojure expressions. It’s not hard to imagine extending the set of federatable storage systems.

Heroku’s Mark McGranaghan talked about viewing logs data. What he really meant was viewing log data as akin to a native data type on Clojure and being able to use Clojure’s built in functions on log data in a natural way. Heroku has built a system call Pulse which takes this view. I particularly liked the small functions that he defined for expressing the intervals for recomputing statistics. It’s the cleanest formulation of that kind of thing that I’ve seen, and it’s enabled by his thesis view and Clojure.

Nathan Marz has been doing some great work at BackType and now Twitter. At StrangeLoop he open sourced Storm, a set of general primitives for doing realtime computation. At the Conj, he was talking about Cascalog, which is a Clojure DSL for Hadoop. Both Cascalog and Storm are in use at Twitter. Cascalog is inspired by Datalog and targets the same space as Pig. Cascalog has the full power of Clojure available to it, as well as the power of Datalog. It’s a little unclear to me exactly how much of Datalog is supported, but this is a powerful idea. Imagine combining the best of Cascalog and the Revelytix system. The source code to Marz’s examples is on Github.

Clojure has a logic programming library, core.logic which is based on the miniKanren system developed at Indiana University by Daniel Friedman, William Byrd, and Oleg Kiselyov. Ambrose Bonnaire-Sergeant presented an excellent tutorial on logic programming in general, and miniKanren in particular. David Nolen talked about predicate dispatching, a much more general way of doing method dispatch, and talked about his plans to tie that together with core.logic. The surprise highlight in this area was that Dan Friedman and William Byrd came to the conference and did a BOF on miniKanren and their constraint extensions to miniKanren. The BOF was surprisingly well attended (over 60 people), due in part to Ambrose’s excellent talk earlier that day. A key philosophical point about miniKanren is that there is a straight forward mechanical conversion from a functional program to logical/relational (miniKanren) program. This looks very promising, and it has me thinking about mashups of miniKanren (core.logic) and Datalog (cascalog). Professor Friedman and his students have done some very important work in the Scheme area over the years, and it was a great experience to meet him and spend some time over dinner. After dinner, we were sitting in the hotel lobby, and David Nolen was walking Friedman and Byrd through the implementation of core.logic, which was ported from the Scheme version of miniKanren, and then optimized for Clojure. There was a free flow of ideas back and forth, and it was a great example of a collaboration between academia and practice (it’s hard to say industry because Nolen and company are doing this in their free time). This is one of the things that I’ve always hoped for around open source, and it was nice to see such a concrete example. MiniKanren is described in Byrd’s PhD dissertation, and in the book “The Reasoned Schemer“.

ClojureScript

ClojureScript is a Clojure compiler which emits Javascript, which is then run though Google’s Closure compiler. I’ve been doing some prototyping work using Node.js and HTML/Javascript, so ClojureScript looks kind of interesting, particularly because it is good at some the data intensive stuff that Javascript is so laborious at. There were three ClojureScript sessions. Chris Houser took us on a deep dive of the compiler, Kevin Lynagh show us some basic applications of ClojureScript in the browser, and David Nolen did a BOF where he showed off the browser connected REPL for Javascript. ClojureScript is still in its infancy, but it’s interesting nonetheless. Once David gets the constraint version of core.logic working in ClojureScript, it should get a lot more interesting.

Community

The thing that stood out to me about the Clojure community was the presence of the “young Jedi”, Anthony Grimes, and Ambrose Bonnaire-Sergeant. Both of them were able to attend their first Clojure/Conj (Anthony’s was last year) due to fundraising campaign initiated by Chas Emerick. Anthony is 17, and Ambrose has not yet graduated from college. Both of them are lead developers on highly technical projects within the Clojure community, and both did a great job of speaking in front of 300+ people who were mostly older than them. When I worked at OSAF, I worked with Stuart Parmenter, who started working in open source when he was 14. It’s great to work with these young, very gifted people, and I love seeing the community welcome and make a space for them.

The flip side of this is that like many open source, programming language oriented conferences, there were very few women in attendance. Perhaps the Clojure community could take a page from the very successful work that my friend Sarah Allen has done on RailsBridge.

Learning More

O’Reilly has finally recanted and is doing a Lisp book. Clojure Programming should be done soon, and Manning has Clojure in Action and The Joy of Clojure. If you are looking for an interactive way of learning Clojure, there is Try Clojure. Those looking to sharpen their Clojure skills can look at the Clojure Koans and 4Clojure .

The speaker slides from the Clojure/Conj 2011 are available on GitHub.

Update: corrected the name of Indiana University – thanks to Lindsey Kuper

Update: linked to a more up to date Overtone repository – thanks to Sam Aaron

NodeConf 2011

Although I was definitely interested in JSConf (writeup), Nodeconf was the part of the week that I was really looking forward to. I’ve written a few small prototypes using Node and some networking / web swiss army knife code, so I was really curious to see what people are doing with Node, whether they were running into the same issues that I was, and overall just get a sense of the community.

Talks

Ryan Dahl’s keynote covered the plans for the next version of Node. The next release is focused on Windows, and the majority of the time was spent on the details of how one might implement Node on Windows. Since I’m not a Windows user, that means an entire release with nothing for me (besides bug fixes). At the same time, Ryan acknowledged the need for some kind of multiple Node on a single machine facility, which would appear in a subsequent. I can see the wisdom of making sure that the Windows implementation works well before tackling clustering or whatever it ends up being called. This is the third time I’ve heard Ryan speak, and this week is the first time I’ve spent any time talking with him directly. Despite all the hype swirling around Node, Ryan is quiet, humble, and focused on making a really good piece of software.

Guillermo Rauch talked about Socket.io, giving an overview of features and talking about what is coming next. Realtime apps and devices are a big part of my interest in Node, and Socket.io is providing an important piece of functionality towards that goal.

Henrik Joreteg’s talk was about Building Realtime Single Page applications, again in the sweet spot of my interest in Node. Henrik has built a framework called Capsule which combines Socket.io and Backbone.js to do real time synchronization of model states between the client and server. I’m not sure I believe the scalability story as far as the single root model, but there’s definitely some interesting stuff in there.

Brendan Eich talked about Mozilla’s SpiderNode project, where they’ve taken Mozilla’s SpiderMonkey Javascript Engine and implemented V8′s API around it as a veneer (V8Monkey) and then plugged that into Node. There are lots of reasons why this might be interesting. Brendan listed some of the reasons in his post. For me, it means a chance to see how some proposed JS.Next features might ease some of the pain of writing large programs in a completely callback oriented style. The generator examples Brendan showed are interesting, and I’d be interested in seeing some larger examples. Pythonistas will rightly claim that the combination of generators and callbacks is a been there / done that idea, but I am happy to see some recognition that callbacks cause pain. There are some other benefits of SpiderMonkey in Node such as access to a new debugging API that is in the works, and (at the moment) the ability to switch runtimes between V8 and SpiderMonkey via a command line switch. I would be fine if Mozilla decided to really take a run at making a “production quality” SpiderNode. Things are still early during this cycle of server side JavaScript, and I think we should be encouraging experimentation rather than consolidation.

One of the things that I’ve enjoyed the most during my brief time with Node is npm, the package management system. npm went 1.0 shortly before NodeConf, so Isaac Schleuter, the primary author of npm, described the changes. When I started using Node I knew that big changes were in the works for npm, so I was using a mix of npm managed packages and linking stuff into the Node search path directly. Now I’m using npm. When I work in Python I’m always using a virtualenv and pip, but I don’t like the fact that those two systems are loosely coupled. I find that npm is doing exactly what I want and I’m both happy and impressed.

I’ve been using Matt Ranney’s node_redis in several of my projects, it has been a good piece of code, so I was interested to hear what he had to say about debugging large node clusters. Most of what he described was pretty standard stuff for working in clustered environments. He did present a trick for using the REPL on a remote system to aid in debugging, but this is a trick that other dynamic language communities have been doing for some time.

Felix Geisendorfer’s talk was titled “How to test Asynchronous Code”. Unfortunately his main points were 1. No I/O (which takes out the asynchrony 2. TDD and 3. Discipline. He admitted in his talk that he was really advocating unit testing and mocking. While this is good and useful, it’s not really serious testing against the asynchronous aspects of the code, and I don’t really know of any way to do good testing of the non-determinism introduced by asynchrony. Felix released several pieces of code, including a test framework, a test runner, and some faking/mocking code.

Charlie Robbins from Nodejitsu talked about Node.js in production, and described some techniques that Nodejitsu uses to manage their hosted Node environment. Many of these techniques are embodied in Haibu, which is the system that Nodejitsu uses to manage their installation. Charlie pushed the button to publish the github repository for Haibu at the end of his talk.

Issues with Node

The last talk of the day was a panel of various Node committers and relevant folks from the broader Node community depending on the question. There were two of the audience questions that I wanted to cover.

The first was what kind of applications is Node.js not good for. The consensus of the panel was you wouldn’t want to use Node for applications involving lots of numeric computation, especially decimal or floating point, and that longer running computations were a bad fit as well. Several people also said that databases (as in implementing a database) were a problem space that Node would be bad at. Despite the hype surrounding Node on Twitter and in the blogosphere, I think that the core members of the Node community are pretty realistic about what Node is good for an where it could be usefully applied.

The second issue had to do with Joyent’s publication of a trademark policy for Node. One of the big Node events in the last year was Joyent’s hiring of Ryan Dahl, and subsequently a few other Node contributors. Joyent is basing its Platform as a Service offering on Node, and is mixing its Node committers with some top notch systems people who used to be at Sun, including some of the founding members of the DTrace team. Joyent has also taken over “ownership” of the Node.js codebase from Ryan Dahl, and that, in combination with the trademark policy is causing concern in the broader Node community.

All things being equal, I would prefer to see Node.js in the hands of a foundation. At the same time, I understand Joyent’s desire to try and make money from Node. I know a number of people at Joyent personally, and I have no reason to suspect their motives. However, with the backdrop of Oracle’s acquisition of Sun, and the way that Oracle is handling Sun’s open source projects, I think that it’s perfectly reasonable to have questions about Joyent or any other company “owning” an open source project. Let’s look at the ways that an open source project is controlled. There’s 1) licensing 2) intellectual property/patents 3) trademarks 4) governance. Now, taking them one at a time:

  1. Licensing – Node.JS is licensed under the MIT license. There are no viral/reciprocal terms to prevent forking (or taking a fork private). Unfortunately, there are no patent provisions in the MIT license. This applies to #2 below. The MIT license is one of the most liberal licenses around – it’s hard to see anything nefarious in its selection, and forking as a nuclear option in the case of bad behavior by Joyent or an acquirer is not a problem. This is the same whether Node is at a foundation or at Joyent.
  2. Intellectual Property – Code which is contributed to Node is governed by the Node Contributor License Agreement, which appears to be partially derived from the Apache Individual and Corporate Contributor license agreements (Joyent’s provision of an on-line form is something that I wish the ASF would adopt – we are living in the 21st century after all). Contributed IP is licensed to Node, but the copyright is not assigned as in the case of the FSF. Since all contributors retain their rights to their contributions, the IP should be clean. The only hitch would be if Joyent’s contributions were not licensed back on these terms as well, but given the use of the MIT license for the entire codebase, I don’ think that’s the case. As far as I can tell, there isn’t much difference between having Node at a foundation or having it at Joyent.
  3. Trademark – Trademark law is misunderstood by lots of people, and the decision to obtain a trademark can be a controversial one for an open source project. Whether or not Node.js should have been trademarked is a separate discussion. Given that there will be a trademark for Node.js, what is the difference between having Node at a foundation or at Joyent? Trademark law says that you have to defend your trademark or risk losing it. That applies to foundations as well as for profit companies. The ASF has sent cease and desist letters to companies which are misusing Apache trademarks. The requirement to defend the mark does not change between a non-profit and a for-profit. Joyent’s policy is actually more liberal than the ASF trademark policy. The only difference between a foundation and a company would be the decision to provide a license for use of the trademark as opposed to disallowing a use altogether. If a company or other organization is misusing the Node.js trademark, they will have to either obtain a license or stop using the mark. That’s the same regardless of who owns the mark. What may be different is whether or not a license is granted or usage is forbidden. In the event of acquisition by a company unfriendly to the community, the community would lose the trademarks – see the Hudson/Jenkins situation to see what that scenario looks like.   
  4. Governance – Node.js is run on a “benevolent dictator for life” model of governance. Python and Perl are examples of community/foundation based open source projects which have this model of governance. The risk here is that Ryan Dahl is an employee of Joyent, and could be instructed to do things a certain way, which I consider unlikely. I suppose that a foundation you could try to write additional policy about removal of the dictator in catastrophic scenarios, but I’m not aware of any projects that have such a policy. The threat of forking is the other balance to a dictator gone rogue, and aside from the loss of the trademark, there are no substantial roadblocks to a fork if one became necessary.

To riff on the 2010 Web 2.0 Summit, these are the four “points of control” for open source projects. As I said, my first choice would have been a foundation, and for now I can live with the situation as it is, but I am also not a startup trying to use the Node name to help gain visibility.

Final thoughts

On the whole, I was really pleased with Nodeconf. I did pick up some useful information, but more importantly I got some sense of the community / ecosystem, which is really important. While the core engine of Node.js is important, it’s the growth and flourishing of the community and ecosystem that matter the most. As with most things Node, we are still in the early days but thing seem promising.

The best collections of JSConf/NodeConf slides seem to be in gists rather than Lanyrd, so here’s a link to the most up to date one that I could find.

Update: corrected misspelling of Henrik Joreteg’s name. And incorrectly calling Matt Ranney Mark.

Strange Loop 2010

Last week I was in Saint Louis for Strange Loop 2010. This was the second year of Strange Loop, which is a by hackers for hackers conference. I’m used to this sort of conference when it’s organized by a single open source community – I’d put ApacheCon, PyCon, and CouchCamp in this category. At the same time, Strange Loop’s content was very diverse, and had some very high quality speakers. It’s sort of like a cross between ApacheCon and OSCON. One difference is that there isn’t a community that’s putting on Strange Loop, and the fun community feel of ApacheCon or PyCon is missing.   

One of the reasons that I was interested in attending Strange Loop was Hilary Mason’s talk on data science / machine learning. This is an area that I am starting to delve into, and I did study a little machine learning right around the time that it was starting to shift away from traditional AI and more towards the statistical approach that characterizes it now. Hilary is the chief scientist at bit.ly, and as it turns out, a Brown alumnae as well. Her talk was a good introduction to the current state of machine learning for people who didn’t have any background. She talked about some of the kinds of questions that they’ve been able to answer at bit.ly using machine learning techniques. Justin Bozonier used Twitter to ask Hilary if she would be wiling to sit down with interested people and do some data hacking, so I skipped the session block (which was painful because I missed Nathan Marz’s session on Cascalog, which was getting rave reviews). We ended up doing some simple stuff around the tweets about #strangeloop. Justin has a good summary of what happened, complete with code, and Hilary posted the resulting visualization on her blog. It was definitely useful to sit and work together as a group and get snippets of insight into how Hilary was approaching the problem.

Another area that I am looking at is changes in web application architecture due to the changing role of Javascript on both the client and the server. I went to Kyle Simpson’s talk on Strange UI architecture, as well as Ryan Dahl’s talk on node.js. Kyle has built BikechainJS, another wrapper around V8, like Node.js. There’s a lot of interest around server side javascript – the next step is to think about how to repartition the responsibilities of web applications in a world where clients are much more capable, and where some code could run on either the client or the server.

Guy Steele gave a great talk, and the number of people who can give such talk is decreasing by the day. As a prelude to talking about abstractions for parallel programming, Guy walked us through an IBM 1130 program that was written on a single punch card. He had to reverse engineer the source code from the card, which was complicated by the fact that he used self modifying code as well as some clever value punning in order to get the most out of the machine. The thrust of his comments on parallel programming was that the accumulator style of programming which pervades imperative programs is bad when it comes to exploiting parallelism. Instead, he emphasized being able to find algebraic properties such as associativity or commutativity which would allow parallelism to be exploited via the map/reduce style of programming pioneered decades ago in the functional programming community, and popularized by systems like Hadoop. Guy was proposing that mapreduce be the paradigm for regular programming problems, not just “big data” problems. For me, the most interesting comment that Guy made was about Haskell. He said that if he know what he knew now when he had started on Fortress, he would have started with Haskell and pushed it 1/10 of the way to FORTRAN instead of starting with FORTRAN and pushing it 9/10 of the way to Haskell.

I’m not generally a fan of panel sessions, because the vast majority of them don’t really live up to their promise. Ted Neward did a really good job of moderating the panel on “Future of Programming Languages”. At the end of the panel, Ted asked the panelists which languages they though people should be learning in order to get new ideas. The list included Io (Bruce Tate), Rebol (Douglas Crockford), Forth and Factor (Alex Payne), Scheme and Assembler (Josh Bloch), and Clojure (Guy Steele). Guy’s comments on Clojure rippled across Twitter, mutating in the process, and causing some griping amongst Scala adherents. The panel appears to have done it’s job in encouraging controversy.

Also in the Clojure vein, I attended Brian Marick’s talk “Outside in TDD in Clojure“. Marick has written midje, a testing framework that is more amenable to the a bottom up style of programming that is facilitated by REPL’s. It’s an interesting approach relying on functions that provide a simple way to specify placeholders for functions that haven’t been completed yet. This also serves as a leverage point for the Emacs support that he has developed.

Doug Crockford delivered the closing keynote. I’ve heard him speak before, mostly on Javascript. His talk wasn’t about Javascript at all, but it was very engaging and entertaining. If you have the chance to see him speak in that kind of setting, you should definitely do it.

A few words on logistics. The conference was spread out across three locations. I feared the worst when I heard this, but it turned out to be fine – OSCON in San Jose was much more inconvenient. The bigger logistical issue was WiFi. None of the three venues was really prepared for the internet requirements of the Strange Loop attendees. WiFi problems are not a surprise at a conference, but the higher quality conferences do distinguish themselves on their WiFi support.

All in all, I think that Strange Loop was definitely worthwhile. The computing world is becoming “multicultural”, and it’s good to see a conference that recognizes that fact.

Haskell Workshop and CUFP 2010

It has been many years since I attended an ACM conference, and even more years since I attended the Lisp and Functional Programming Conference, which has evolved into the International Conference on Functional Programming (ICFP). ICFP was in the United States this year, and I’ve wanted to drop in for quite some time. There are many ideas pioneered by the functional programming community, and as much as possible I like to go to the original sources of ideas. ICFP is a long conference with many attached events, and it turns out that the best use of my time was to drop in for the Haskell workshop at the tail end of the conference, and the Commercial Users of Functional Programming (CUFP) conference.

Haskell Workshop

I’ve been around long enough to remember when Haskell first came out, and despite my stint as a database programming languages grad student, I’ve never had the chance to really give Haskell the attention that I feel it deserves. 20 year since its appearance Haskell is still barely on the radar. At the same time, I heard some very interesting talks at the workshop. Things like the Hoopl library for implementing dataflow optimzations in compilers, and the Orc DSL for concurrent scripting. The Haskell systems hackers have made great progress and doing some great work. Bryan O’ Sullivan described his work on improving GHC’s ability to handle lots of long lived open network connections. Given the recent burst of interest in event based programming models, such as Node.js, this is an interesting result. Simon Marlow presented a redesign of the Evaluation Strategies mechanism that GHC uses to control parallelism. Many of the talks that I heard have ideas that are applicable to problems that exist in modern systems. I just wish that I could see a path the involved using Haskell itself to solve those problems instead of the ideas migrating into another language/system.

Surgecon

Unbeknownst to me, my friend Theo Schlossnagle ran Surge, a conference on scalability, in Baltimore, and it overlapped the parts of ICFP that I attended. Surge seems to have flown pretty low under the radar. Google doesn’t return many relevant results for it, and the best information (other than talking to Surge attendees) I’ve been able to find on Surge is on Lanyrd. Theo told me that he was counting on this year’s attendees to be his PR for next year. I didn’t attend, but based on the tweets and dinner conversations, it sounds like it was great. I had dinner/beers with some Apache folks who were in town for Surge, as well as some Surge attendees like Bryan Cantrill. The “systems guys” gave me a good ribbing about being at a conference for “irrelevant languages”, and I had a really good conversation with Bryan about Node.js, cloud computing, and the Oracle acquisition (ok, that part wasn’t so good). Node.js is on a lot of people’s minds at the moment, and it was good to hear Bryan’s perspective on it. It was an interesting sidebar to the immersion in functional programming. I do think that in the medium term there are some interesting connections between Node and FP, but that ‘s probably an entire post of its own.

CUFP

There was a lot of F# related content at CUFP, and I think that Microsoft deserves kudos for the work that they are doing. I think it’s pretty clear that shipping F# in the box with Visual Studio 2010 is not a huge money maker for Microsoft at this point, and I’m impressed with their willingness to take a long term view of the future of programming. Unfortunately I’m not a Windows ecosystem person, so as attractive as F# and Visual Studio are, I doubt that I’ll be playing with this anytime soon.

Marius Eriksen‘s talk on Scala at Twitter was interesting because of the way that he described the conceptualization of Rockdove operations as folds, taking clear advantage of the benefits offered by a functional style. He also had some thought provoking comments about giving applications access to the behavior of the garbage collector. There are some interesting possibilities if you start to give developers control of the behavior of various parts of the runtime system.

Michael Fogus talked about his company’s experience using Scala. His talk was pretty entertaining, and there were some interesting comparisons between Scala features that they thought would be useful and Scala features that actually turned out to be useful. My only issue with his talk was the size of the sample, which isn’t something that he could do anything about. This was also true of the talk by the Intel compiler folks.

I’ve seen a number of talks on the Microsoft Reactive Extensions, mostly with respect to JavaScript. I continue to believe that RxJS could be a great help to Javascript programmers, particularly as things like Node.js take hold. Matt Podwysocki’s Node.js file server example shows how.

Warren Harris from Metaweb talked about his use of monads, arrows, and OCaml to build a more efficient query processor for Freebase’s MQL query language. This was a really interesting talk, because query optimization was the topic of my graduate school research, and at the time the connections between query languages and functional programming were a relatively new topic.

Final thoughts

It doesn’t take much to fan the flames of functional love in me. There are lots of smart people working on beautiful and interesting solutions. I wish that I could see a better path for those ideas to make it into mainstream practice.

JSConf US

I spent the weekend in Washington, DC attending JSConf.US 2010. I wasn’t able to attend last year, due to scheduling conflicts. Javascript is a bit higher on my radar these days, so this was a good year to attend.

The program

The JSConf program was very high quality. Here are some of the talks that I found most interesting.

Yahoo’s Douglas Crockford was up first and describe Javascript as a “a functional language with dynamic objects and a familiar syntax”. He took a some time to discuss some of the features being considered for the next version of Javascript. Most of his talk was focused on the cross site scripting (XSS) problem. He believes the solving the XSS problem should be the top priority of the next version of Javascript, and he feels that this is so urgent that we ought to do a reset of HTML5 in order to focus on this problem. Crockford thinks that HTML5 is only going to make things worse, because it adds new features / complexity. He called out local storage as one feature that would introduce lots of opportunity for XSS exploits. I was very surprised to hear him advocating a security approach based on capabilities. He mentioned the Caja project and his own proposal at www.adsafe.org. He stated that “ECMAScript is being transformed into an Object Capability Language; the Browser must be transformed into an Object Capability system”. This was a very good talk, and it caused a swirl of conversation during the rest of the conference.

Jeremy Ashkenas talked about Coffeescript, which is a language that compiles into Javascript. It has a very functional flavor to it, which was interesting in light of Crockford’s description of Javascript. It also seemed to be influenced by some ideas from Python, at least syntactically. I really liked what I saw, but I’m wary of the fact that it compiles to Javascript. I am not bothered by languages that compile to JVM bytecode, but somehow that feels different to me than compiling to Javascript. I’m going to spend some time playing with it – maybe I’ll get over the compilation thing.

Gordon is a Flash runtime that is implemented in Javascript.   Tobias Schneider caused quite a stir with his talk. He showed several interesting demos of Gordon playing Flash files that were directly generated by tools in the Adobe toolset. Tobias was careful to say that he doesn’t yet implement all of flash, although he definitely wants to get full support for Flash 7 level features. It’s not clear how Gordon would handle newer versions of Flash, because of the differences beween Javascript and Actionscript. Bridging that gap is probably a whole lot of work.

Since 2008 I’ve had several opportunities to hear Erik Meijer talk about his work on Reactive Programming at Microsoft. He’s talked about this work in the context of AJAX, and a common example that he uses is autocompletion in the browser. Jeffrey Van Gogh came to JSConf to talk about RxJS , a library for Javascript which implements these ideas and provides a better experience for doing asynchronous programming, both on the client and server side. In his talk Jeffrey described RxJS bindings for Node.js.  I also met Matt Podwysocki, who I’ve been following on Twitter for some time. Matt has been writing a series of blog posts examining the Reactive Extensions. One hitch in all of this is that the licensing of RxJS is unclear. You can use RxJS in your programs and extend it but it’s not open source, and you can’t distribute RxJS code as part of an open source project. I’m interested in the ideas here, but I haven’t decided whether I am going to actually click on the license.

I dont’ remember the first time that I heard about SproutCore, but I really started paying attention to it when I saw Erich Ocean’s presentation at DjangoCon last year. The original speaker for SproutCore couldn’t make it, but Mike Ball and Evin Grano, two local members of the SproutCore community stepped in to give the talk. Their talk was heavy on demonstrations along with updates on various parts of SproutCore. They showed some very interesting UI’s that were built using SproutCore. The demo that really got my attention was related to the work on touch/multiouch interfaces. NPR had their iPad applications in the App Store on the iPad launch day. Mike and Evin showed a copy of the NPR application that had been built in 2 weeks using SproutCore. The SproutCore version can take advantage of hardware acceleration, and seemed both polished and responsive. Dion Almaer has a screenshot of the NPR app up at Ajaxian.

Raphaël is a Javascript toolkit for doing vector based drawing. It sits on top of either SVG or VML depending on what browser is being used. In the midst of all the hubub about Flash on Apple devices, Dmitry Baranovskiy, the author of Raphaël pointed out that Android devices don’t include SVG, and thus cannot run Raphaël. Apparently people think of Raphaël as something to be used for charts but Baranoskiy showed a number of more general usages of vector drawing that would be applicable to every day web applications.

Steve Souders works on web client performance at Google and has written several books about this topic. His presentation was a conglomeration of material from other talks that he has done. There were plenty of useful tidbits for those looking to improve the performance of their Javascript applications.

Billy Hoffman‘s talk on security was very sobering. While Crockford was warning about the dangers of XSS in the abstract, Hoffman presented us with many concrete examples of the ways that Javascript can be exploited to circumvent security measures. A simple example of this was a simple encoding of javascript code as whitespace, so that inspection of a page’s source code would show nothing out of the ordinary to either an uninformed human or to a security scanner.

In the past, Brendan Eich and I have had some conversations in the comments of my blog, but I don’t recall meeting him in person until this weekend. Chris Williams snuck Brendan into JSConf as a surprise for the attendees, and many people were excited to have him there. Brendan covered a number of the features being worked on for the ECMAScript Harmony project, and he feels that the outlook for Javascript as a language is improving. Someone did ask him about Crockford’s call to fix security, and Brendan replied that you can’t just stop and fix security once for all time, but that you need to fix things at various levels all the time. His position was that we need more automation that helps with security, and that the highest leverage places were in the compiler and VM.

I’ve been keeping an eye on the server-side Javascript space. Ever since the competition between Javascript engines heated up two years ago, I’ve been convinced that Javascript on the server could leverage these new Javascript engines and disrupt the PHP/Ruby/Python world. If you subscribe to that line of thinking, then Ryan Dahl’s Node.js is worth noting. Node uses V8 to provide a system to build asynchronous servers. It arrived in the scene last year, and has built up a sizable community despite the fact that It is changing extremely rapidly – Ryan said he would like to “stop breaking the API every day”. In his presentation Ryan showed some benchmarks of Node versus Tornado and nginx, and Node compared pretty favorably. It’s not as fast as nginx, but it’s not that much slower, and it was handily beating Tornado. He showed a case where Node was much slower because V8′s generational garbage collector moves objects in memory. In the example, node was being asked to serve up large files, but because of the issue with V8, it could only write to the result socket indirectly. Ryan added a non-moving Buffer type to Node, which then brought it back to being a close second behind nginx. I was pleased to see that Ryan is very realistic about where Node is at the moment. At one point he said that noone has really built anything on Node that isn’t a toy. If he gets his wish to stabilize the API for Node 0.2, I suspect that we’ll see that change.

Jed Schmidt is a human language translator for his day job. In his off hours he’s created fab.js a DSL for creating asynchronous web applications in Node. Fab is pretty interesting. It has a functional programming flavor to it. I’m interested in comparing it with the RxJS bindings for Node. It’s interesting to see ideas from functional programming (particularly functional reactive programming) percolating into the Javascript server side space. In some ways it’s not surprising, since the event driven style of Node (and Twisted and Tornado) basically forces programmers to write their programs in continuation passing style.

I didn’t get to see Jan Lehnardt’s talk on evently, which is another  interesting application of Javascript (via JQuery) on the server side. I need to make some time to go back and watch Chris Anderson’s screencast on it.

The conference

As far as the conference itself goes, JSConf was well organized, and attendees were well taken care of. The conference reminds me of PyCon in its early days, and that’s my favorite kind of conference to go to. There was very little marketing, lots of technical content, presented by the people that are actually doing the work. I heard lots of cross pollination of ideas in the conversations I participated in, and in conversations that I heard as I walked the halls. I especially liked the idea of “Track B” which was a track that got assembled just in time. It’s not quite the same thing as PyCon’s open spaces, but it was still quite good. Chris and Laura Williams deserve a big hat tip for doing this with a 10 person staff, while closing on a house and getting ready for their first child to arrive.

Last thoughts

The last two years have been very exciting in the Javascript space, and I expect to see things heating up quite a bit more in the next few years. In his closing remarks, Chris Williams noted that last year, there was a single server side Javascript presentation, and this year the content was split 50/50. This is an area that you ignore at your own risk.


DjangoCon 2009

Last week I attended DjangoCon 2009 in Portland. Due to scheduling conflicts, I wasn’t able to attend DjangoCon last year, and I was disappointed that I missed that inaugural event. I’ve seen some Django stuff at PyCon, and I’ve written some Django code, being at a conference like DjangoCon helps me to understand the community and technology in a way that just reading the documentation doesn’t.

Talk Highlights

Here are some of the talks that I found notable:

Shawn Rider and Nowell Strite of PBS gave a talk titled: Pluggable, Reusable Django Apps: A Use Case and Proposed Solution. I think that very few people in the Django community had any idea that Django was being used extensively in PBS. That definitely falls into the category of pleasant surprises.    One of the strengths of Django is the focus on building small single purpose applications which can be used to build up larger applications. Doing this is harder than it sounds, and Shawn and Nowell described some of the problems that they ran into, as well as showing some ways of dealing with those issues. There was some crosstalk between the PBS guys and the Pinax developers, who are also doing a lot with reusable apps. I hope that these folks will work to share and combine their knowledge and then disseminate that to the broader Django community.

There were a number of talks which followed the theme of “how not to use parts of Django”. It’s interesting because people like Django, and even if they don’t like some parts, they want to use the rest, and are willing to work to make that possible. You would expect people to just walk away from the framework in cases like these.

Eric Ocean, one of the developers of SproutCore gave what I considered to be a pretty interesting talk. Unfortunately, his talk didn’t have much of a connection to Django, other than to suggest some things that Django could do to support SproutCore better. I know from watching the IRC and Twitter back talk, that people were put off by the style of presentation (a little too like a commercial), and the weak connection to Django. SproutCore is interesting to me because it’s at a different level than most of the Javascript frameworks. It’s at a higher level, which I think will be necessary as browser based applications become more sophisticated. I know that I am going to be taking a closer look at SproutCore, and I hope that a useful Django/Sproutcore collaboration will emerge from the sprints.

Simon Willison gave a keynote about Cowboy programming. The big piece for me was his description of how the Guardian built an application to help the public scrutinize the expenses of British MP’s. There’s something about these situations that appeals to me, against my knowledge and better judgment of “sound software engineering practices”. I guess it’s a guilty pleasure of sorts.

Ian Bicking gave a keynote which might be described as “a free software programmer’s midlife crisis”. Ian was very philosophical and reminded us that free software (as opposed to open source software) was rooted in a set of moral (not economic or process) imperatives. It was a very thoughtful speech, and I think that its worth several reads of his text (something which is hard to do on a train ride with an iPhone) and some additional ponderings.

Avi Bryant’s keynote took its root in his experiences building Trendly. As one might expect, Avi started building Trendly using Seaside. But by the time he finished, he noticed that very little of Seaside was actually being used. He attributed this to the fact that Trendly’s architecture involves loading a single HTML, with a ton of Javascript. That Javascript then manages all of the interaction with the server, which consists of snippets of JSON data. This range true to me because we used a similar architecture for Chandler Hub, the web based version of Chandler (our interaction with the server was based on atom and atompub, not JSON), and it’s the kind of architecture that GMail is based on. Avi also treated us to a demonstration of Clamato, his Smalltalk dialect that compiles to Javascript. Again, another attempt to deal with the challenges of engineering large Javascript applications in a web browser.

There were plenty of other good talks, and many of the slides are already available.

My keynote

I’m afraid that I am not equal to the task of writing out my presentation text in full as Ian and Jacob have done, so you will have to settle for the highlights and wait until the video appears.

My keynote was organized around two major sections.

The first section was a look at what I see in the Django community at present. This includes a look at some pseudo statistics around job postings and a poll of web frameworks being used by startups in an effort to get some view into whether and how much adoption of Django is happening. The short answer is that things look promising, but there is still plenty of room to grow. On the technology side, I pointed out the emphasis on combining applications and the work of the Pinax and PBS folks. The other major technology thing that I called out was GeoDjango, which is undoubtedly the most sophisticated GIS functionality in any web framework in any language or platform. This is going to be very attractive to people building location aware mobile apps, and I showed two examples of augmented reality applications as illustrations. This section ends with some observations about the Django community, using the PyCon sprints as an example. Ok, there are also some lighthearted slides about Django’s mascot, the djangopony.

The remainder of the talk was about the ways that web applications are changing and how Django might adapt to them. There are (at least) three groups of people that will be impacted by these changes. From the view point of users, the two big things are richer, more interactive applications, and access from location enable devices. Developers are going to need help in dealing with these new requirements, and the people who operate web applications need much more support than they currently have.   

I see several technologies that will be important in facilitating these changes. The first of these is some Rich Internet Application technology. The second is API’s to web applications. A digression on this point. When the iPhone was introduced, the only way to develop applications was using web technologies. This made a lot of people very angry, and Apple followed up with the ability to build native platform applications. It should be possible to build rich web interfaces on the iPhone. My observation is that given the choice beween a rich web interface and a native iPhone application, users pick the native application. Look no further than the furor over the native Google Voice application. The native applications are talking to the servers using API’s. Those API’s are not just cool Web 2.0 frosting. The last technology is cloud computing, which started out as a deployment/operations technology and is now moving up to impact application development at many levels.

In light of this, what are framework developers to do? I did a quick survey of several web frameworks which have interesting ideas or approaches in them, so that the Django folks could see what their “competitors” are up to. The frameworks that I included are Rails, Lift (Scala), Webmachine (Erlang), Nitrogen (Erlang), CouchApps (CouchDB + JavaScript – this isn’t quite a framework in the traditional sense, but it met the spirit of my criteria), and Javascript. In the case of Javascript, the observation is that the rapid increase in Javascript performance coupled with a good Javascript framework leads to something which is economically attractive (same technology in the server and client).

The talk finishes with a set of proposals for “science projects” that might be attempted in the context of Django. Some of what I outlined is emerging, and in some cases speculative. Django doesn’t need to blow itself up and start over. Instead, what’s needed is for people with Django sensibilities to look some of these problems and see if a Django flavored solution can be found. Here’s the list of projects:

  1. Asynchronous Messaging – if there’s any use of messaging, it’s typically to do jobs in the background. What would happen if we made the use of messaging pervasive throughout the framework?
  2. Comet – I think that the Django+orbited approach to Comet is limited in comparison to what you see in Lift or Nitrogen. Can Django do Comet support at the same level (or better) than these frameworks? What would happen if the Comet stuff were hooked up directly to the messaging stuff I just described? Imagine the equivalent of urls.py that routed Comet requests to messaging.
  3. REST – There are several good packages for dealing with REST in Django. It would be nice to have this all packaged up neatly and made available for people.
  4. Deployment – This is really a mess. Are there changes that could be made to Django to make it easier to deploy, or to work better with tools like Puppet, Chef, Fabric, etc?
  5. Monitoring – Typically frameworks provide very little monitoring information. It seems like there is a lot that could be done here.
  6. Analytics – Once you have raw monitoring information, the next step is to do some analytics on it. Django is famous for creating admin UI’s with a very small amount of effort. What if we applied that same thinking to analytics?
  7. Cloud – If you add up the first 6 items, you are well on your way to what might be a cloud friendly framework. There is still some work to do in terms of making applications on the framework adapt to elastic deployment scenarios, but it would be a good step.
  8. Stacks – A very basic step towards cloud stuff would be to build a preconfigured stack of software to run/develop a Django app. This is a controversial idea, because everyone has their own idea of what software should be in such a stack, and how all the configuration switches should be set. I still that having one (or more) such stack would help more than it would hurt. In my ideal world this stack would be delivered as a virtual machine image that could also be uploaded to cloud providers.
Here are the slides:


All of the talks were videotaped so those of you who were unable to attend will be able to catch up soon.
I had a great time hanging out with the Djangonauts. My thanks to Leah Culver and Robert Lofthouse for inviting me to speak.

Re: Snakes on the Web

Jacob Kaplan-Moss, one of the BDFL’s for Django has published the text and slides for his upcoming talk(s) “Snakes on the Web” at PyCon Argentina and PyCon Brazil. Jacob says that he’s trying to answer three questions:

  1. What sucks, now, about web development?
  2. How will we fix it?
  3. Can we fix it with Python?

There’s some good stuff in here, and it’s definitely a worthwhile read.

Jacob is in South America, which means he won’t be at DjangoCon next week. I was disappointed about that before I saw his talk, and I’m even more disappointed now. I’ll be giving the last keynote at DjangoCon, and I’ll be discussing some thoughts and ideas for where Django (and other web frameworks) might go next. It would have been a great opportunity to carry on the conversation in person. I guess we’ll be doing by blog instead.

One of the topics that Jacob covered in his talk was concurrency, and he pointed to my OSCON talk on concurrency constructs as something that has influenced his thinking. I do think that he got the wrong idea from my conclusion. At the moment I don’t see a clear solution for concurrency, but I don’t believe that the situation is hopeless, either. I think that we are looking at a period where we have a lot of experimentation, and I think that’s a good thing. It is way premature to say that we have a solution, and I’d rather people keep experimenting.

I have some more thoughts on some of Jacob’s points, but those are in the keynote, so I’ll save those until after I’ve actually given the presentation at DjangoCon on Thursday. I suspect that the other keynote speakers, Avi Bryant, and Ian Bicking to have some thoughts in this general direction as well.    I think it would be great to have an open space on these topics sometime on Thursday.

Erlang Factory 2009

I spent Thursday and Friday of last week at the Erlang Factory in San Francisco (although the event was actually in Palo Alto).

Why did I go?

I’ve written about Erlang in this space before. Erlang is having a major influence on other languages, such as Scala on the JVM side and Axum on the CLR side. In addition every language seems to have several implementation of Erlang style “actors” (despite the fact that this is historically incorrect). Erlang has been around for a long time, and has seen industrial usage in demanding telecom applications. As a dynamically typed functional language with good support for concurrency and distribution, it is (if nothing else) a source of interesting ideas. Earlier this year, my boss asked me to start doing some thinking about cloud computing in addition to the stuff that I was already doing around dynamic languages — another good match for Erlang. This was the first large scale gathering of Erlang people in the US (at least that I am aware of), so I wanted to drop in and see what was going on, what the community is like, and so on.

Talks

The program at the Erlang Factory was very strong. In many of the slot sessions, there were 3 excellent talks to choose from. Every single talk that I went to was of very high quality. It was so bad that I wasn’t able to explore all the areas that I wanted to. Fortunately, the sessions were videotaped and are supposed to be made available on the web. Also, there was a decent amount of twittering going on, so a Twitter search for #erlangfactory will turn up some useful information.

I attended a number of “experience” talks by companies / individuals. There were experience talks from Facebook, SAP, Orbitz, and Kreditor (the fastest growing company in Sweden). I made it to the Facebook talk and the Kreditor talk. Facebook’s usage/deployment is on the order of 100 machines, which provide the chat facility for Facebook. Erlang is doing all the heavy lifting, and PHP is doing the web UI part. There was a lot of this kind of architecture floating around the conference. It seemed like the most popular combination was Ruby/Erlang, but there was definitely Python and PHP as well. The Kreditor talk was interesting because their site has been running for 3 years with very small amounts of downtime. Unfortunately, their entire deployment is probably less than 10 machines, so that blunts the impressiveness of what they have done. Still it was interesting to hear how they accomplished this using features of Erlang. In addition to the talks, I spoke with many attendees who are using Erlang in their companies. One such person was eBay founder Pierre Omidyar, who is running Ginx, a web based Twitter client. Pierre is doing the coding and deployment of the site, and was well versed in the Erlang way of doing things. An interesting data point.

The Erlang community (like all communities) has it’s old guard. These are folks who have worked with Erlang for years, before its recent burst of interest. There were a pair of keynotes by Erlang long-timers Robert Virding (The Erlang Rationale) and Ulf Wiger (Mulitcore Programming in Erlang). Both of these talks shared a common trait — the speakers were pretty honest about what was good about Erlang, and where there were problems. Given how prone the computing business is to fashion, I found this to be refreshing. Virding talked about the reasons why Erlang is designed the way it is. He accepted the blame for inconstencies in the libraries, talked about the need to avoid the process dictionary, and agreed that “a char type is probably not wrong”. Wiger’s talk was about why parallelizing code is hard (even with Erlang). He used the example of parallelizing map to demonstrate this, and showed the use of the QuickCheck testing tool to aid in finding parallelism bugs. The Erlang version of QuickCheck was inspired by the Haskell version of QuickCheck, and it’s a very very useful tool. The adaptations for parallelism look very nice. It’s a shame that the Erlang version is commercial software. I don’t grudge the authors the right to charge money for their software, but I do think that this will hold back adoption of this important tool.

There were many talks on what I would describe as “cloud problems”. For example, Ezra Zygmutowicz’s “You got your Erlang in my Ruby” was really about how he built a self assembling cluster of Ruby daemon’s (Nanite), Dave Fayram and Abhay Kumar’s “Building Reliable Distributed Heterogenous Services with Katamari/Fuzed“, and Lennart Ohman’s “A service fail over and take-over system for Erlang/OTP”. Like PyCon, there was a lot of interested in eventually consistent databases/key-value stores/non-relational databases. Cliff Moon’s talk on dynomite (a clone of Amazon’s Dynamo system), was particularly encouraging because he was reaching out to other people in the audience (and there were a decent number of them) to try an consolidate all their efforts into a single project. From what I could tell, people seemed receptive to that idea.

CouchDB also fits into that last category of non-relational databases, but it gets it’s own paragraph. One reason is that I helped mentor the project through the Apache Incubator (and chauffeured those CouchDB committers who were present). Another is that CouchDB creator Damien Katz got a keynote. Third is that there was basically a CouchDB track on the second day of the conference. There was a lot of interest in CouchDB, and a lot of activity as well. I was told that some of the people who took the CouchDB training during the training days had actually submitted patches on the project already. Damien’s talk was not about the technical details of CouchDB, but about his personal journey to CouchDB, which included selling his house and living off his savings in order to see CouchDB come to life.

Activity has really picked up in the Erlang web framework space. In addition to Erlang Web, and Yariv Sadan’s Erlyweb, there is also Rusty Klophaus’ Nitrogen. Nitrogen focuses more on the UI side of the web framework, omitting any kind of data storage. It’s very easy to create an AJAX based user interface using Nitrogen, and there is nice support for Comet. As part of his presentation, Rusty showed his slides on a Nitrogen based webcast reflector. You specify the UI using Erlang terms, which then causes HTML/Javascript/etc to be generated, which caused a stir in part of the Twitter peanut gallery. I was mostly happy to see people focusing on solving the current generation of problems. My favorite web space talk was probably Justin Sheehy’s talk on Webmachine. I think that I prefer the description of WebMachine as a REST or HTTP toolkit. Webmachine gives you what you need to implement any HTTP method correctly, and then provided a set of callback functions that can be implemented to customize that processing to do actual work. One of the coolest things about Webmachine is it’s ability to visually show you that path taken in processing a particular HTTP request, and being able to inspect/dump data at various points in the diagram. It makes for a very nice demo.

There were not that many “language geek” talks. This contrasts with the early years of PyCon (at least for as long as I have attended) where there were quite a number. I missed Robert Virding’s talk on Lisp Flavored Erlang (but I saw some example usage in a CouchDB talk), because it overlapped the dynomite talk. I was able to attend Tony Arcieri’s talk on “Building Languages on Erlang (and an introduction to Reia)”. During the first part of his talk, Tony showed how to construct an Erlang module on the fly in the Erlang shell. He then discussed some tools which are useful to people trying to build languages on top of BEAM, the Erlang virtual machine:

  • Robert Virding has written leex, a lexical analyzer generator
  • yecc, a Yacc style parser generator is included in the Erlang distribution
  • the erl_syntax_lib library aids in constructing Erlang abstract syntax trees, which can then be compiled to Erlang bytecode.
  • Erlyweb contains the smerl (simple metaprogramming) library for creating and manipulating Erlang modules at runtime.

After that, he launched into a description of REiA. I’m not sure that I agree with some of the choices that he has made, but I am happy to see people experimenting with languages on top of BEAM, and in keeping with Erlang’s process model and the OTP infrastructure. One of the things that Tony mentioned was abandoning indentation based syntax. He wrote an entire postmortem on that experience in his blog. Python’s indentation based syntax has won me over and made me a fan, and I am sad to see that indentation syntax, blocks/closures, and expression orientation continue to be at odds.

Coda

It looks like Erlang is starting to find a home. Companies are using it in production. There are books starting to be written about it. Many (not all) of the things which make Erlang seem odd to “mainstream” programmers also appear in languages like Scala, Haskell, and F#. At the same time, Erlang has a long history of industrial deployment, albeit in a single (large) market segment. Many of the problems which we now face in large web systems (and the cloud): concurrency, distribution, high availability, and scalability are strengths for Erlang. Indeed, many of the people that I heard from or talked to basically said that they couldn’t solve their problem with any other technology, or that their solutions were dramatically simpler than the technologies that they already knew. Will that be enough to propel Erlang into the mainstream? I don’t know. I also don’t know if our current state of mainstreamness is going to remain. More and more I’m seeing an attitude of “let’s use the best tool for the job”, not only in languages, but in all parts of (web) applications.

There’s also the issue of the Erlang community itself.   Around 120 people showed up for the conference. As I mentioned previously, there are the folks who have been doing Erlang for years. Then there are the relative newcomers, who are web oriented/web savvy, and solving problems in very different domains than the original problem domain of Erlang and it’s inventors. Thus far, the two segments seem to be getting along fine. I hope that will continue — success or the potential for success has a tendency to bend relationships.

Best PyCon Evar

I probably should have chosen a different title for this post, because at the rate things are going for PyCon, I’ll just have to use the same title again for the next few years. This year, PyCon happened during the same week as ApacheCon EU (the 10th anniversary of the ASF), and EclipseCon. I have a slight bit of regret that I wasn’t at ApacheCon for the 10 year anniversary, but I’m planning to be at the 10th anniversary celebration at ApacheCon US in Oakland, in November. That roughly corresponds to the time when first got involved with Apache and open source, so it will be pretty meaningful. Beyond that, it was hands down for PyCon, my favorite conference. Even if the PyCon organizers hadn’t invited me to speak on a topic of my choosing, there are just so many things to love about PyCon.

The Talks

PyCon 2009

Despite a very active and fun hallway track, I did go to a number of talks.   

I went to Adam Christian and Mikeal Rogerstalk on Windmill mostly for moral support. We worked together at OSAF, and I like Windmill, and it’s really good to see Windmill picking up steam in the Python and other communities. If you are looking for a web testing framework, particularly one that is string at AJAX applications, you owe it to yourself to look at Windmill.

There were a few tools talks that I attended. I use IPython, so I was curious to see how Reinteract: a better way to interact with Python, would improve on IPython. I like the Visicalc/TkSolver like worksheet that allows you to change values in a Python interpreter history and have values propage forward. I’d love to see all these REPL tools come together in an integrated way. We might finally get back to the functionality of the Lisp Machine REPLs someday. I also attended How AlterWay releases web applications using “zc.buildout“ since Jacob Kaplan-Moss warned me that the zc.buildout documentation was sorely lacking. Even that talk wasn’t enough to get me going, but the sprints produced some great new documentation for buildout. I’m looking forward to digging into that.

Some talks dealt directly with topics that are relevant to work, particularly now that the dynamic languages folks at Sun are now a part of the Cloud Computing division. These talks included:

  • Twisted AMQP and Thrift: Bridging Messaging and RPC for building scalable distributed applications – Twisted bridges to AMQP and Thrift.

  • Concurrency and Distributed Computing with Python Today – Jesse Noller did a great job surveying the various offerings available in Python today. There’s a lot of stuff there, but I think that there’s still quite some way to go yet. That’s not picking on Python, that’s just my general view of this space.

  • Drop ACID and think about data – Bob Ippolito did a really nice survey of the various non-relational/non-transactional data storage options out there. Bob actually tried many of these, so the survey is useful for weeding out systems aren’t really ready for prime time. A must view if you haven’t been paying attention to this space.

  • Pinax: a platform for rapidly developing websites – I’ve been following Pinax via Twitter for some time now, and James Tauber and I were involved at the beginning of the Apache XML project almost 10 years ago. Despite all that, we’ve never actually met in person until this week. James had a tough job with his talk. Pinax is very new, so he could either talk for the people who didn’t know what Pinax is, or he could talk to people wanted to know where things were. James knew this was going to be a problem and said so in his talk. And it was, at least for me. Fortunately, I managed to sit down with James at the sprints and get my questions answered. Zed Shaw recently wrote a (very positive) review of Django. That’s interesting since Zed was a hard core Rails guy. It’s also interesting because he called out Django’s emphasis on modularity and Pinax as an example of that modularity. My questions about Pinax were mostly about what (if anything) Pinax has done to build on the modularity provided by Django. At the moment, the various Pinax components cooperate mostly via conventions. Things are still early in Pinax, and I wasn’t surprised to hear this. James did say that some conventions were close to getting codified/documented/supported by the framework, which is what I am really interested in. In some ways, the data representation and modularity problems are similar to the kinds of problems that we were trying to solve for Chandler. Pinax is in the social application domain and Chandler is in the PIM domain, so while there are some similarities there are also differences. I’ll definitely be sticking my nose a bit deeper into the Pinax checkout that’s been sitting on my hard disk.

The most entertaining talk that I attended was Ian Bicking’s Topics of Interest. Ian took the invitation to speak on something of interest quite literally which created an air of mystery. In the end, Ian prepared some slides (some of which were quite thoughtful and introspective), used an instance of the new Google Moderator to queue up some audience questions, and created an IRC backchannel which he kept on the screen during his talk. The result has to be watched (and the video is already up) to be understood. It was quite hilarious, with the exception of some unpleasant commentary after someone in IRC asked “why aren’t there more women at PyCon”. The resulting IRC conversation only serves as an explanation for why. Many people felt this way, and discussion of this spilled out into Twitter, and I hope that perhaps we can change things for the better.

I gave my talk, Challenges and Opportunities for Python, and got a pretty good reception. I had a number of hallway and other conversations with people based on the content. I think that I was successful in giving people a perspective on the dynamic language world as a whole, on Python’s place in it, and some things that we might be able to do in order to grow. You can watch the video and make your own assessment, and decide if there are actions worth taking.

This year the conference is benefitting from a great new website (built in Django), and you’ll find the slides and video for each talk on the links. The video team is doing a great job of cranking out the video, so all of them should be up soon, or you can go to pycon.blip.tv to see them all together. Here are some talks that I am going to be checking out:

The Lightning Talks

PyCon 2009

I put the lightning talks in a separate category from the talks because they are a phenomenon at PyCon. This year there were two lightning talk sessions, one at the beginning of each day and one at the end of each day. That’s 6 sessions of lightning talks! Jacob Kaplan-Moss only allowed signups for the next session, and it was truly first come first serve (without last year’s arrangement with the sponsors). There were a number of really good lightning talks. There really isn’t a good record of what got presented except perhaps on Twitter. A search for #pycon should get most of it.

Update: the lightning talks were also video’ed and will be posted on pycon.blip.tv

The Sprints

The PyCon sprints remain a phenomenon. While I don’t think quite as many people stayed this year as last year, there were still a lot of people — enough to fill the basement conference rooms at the Crowne Plaza hotel, and enough to need one of the ballrooms to serve lunch and dinner in. Once again, I hung at the Jython sprint, and wandered in and out of the Django and Pinax sprints. During the two days of sprints that I stayed for, I observed the folks working on ctypes for Jython actually crashing the JVM. SQLAlchemy started to really run on Jython and so did Twisted. Four days of hacking with the core developers of a project generally tends to produce results. So does spending time to bring new people from the community into your project.

I reported a bug in Django as I tried to get buildout setup to do Django on MySQL. I’m talking about Python and MySQL at the MySQL conference in a few weeks, so I was working on my example code. Turns out that MySQLdb doens’t build cleanly on the Mac. The trunk version almost builds cleanly, so I used that, but that version chokes something in Django. Before I discovered that I had done some gymnastics involving a git-svn clone of MySQLdb, a push of that to github, and a git recipe for buildout. I never quite got the git/buildout part working and I decided that it was overkill and that’s when I finally discovered that the trunk didn’t work with Django.

Of course, the sprints are also a time to catchup with/meet people in the community. It’s a time when there are friendly rivalries, joking, and alcohol. One of the momentous occasions during 2008, was that Django got a pony.

The exuberant Django people decided to bring the pony to PyCon…

PyCon 2009

Guido decided that he wanted the pony…

PyCon 2009

This all made for great fun and entertainment, which then spilled over into the sprints as a three way Python Core/Django/Pinax feud, which lead to things like this and this. This is hard core fun, people.

Overall Conference Commentary

The organizers estimated the attendance for this year’s PyCon at around 900 people. That’s a slight decline from last year, but the economic situation is much much worse than it was last year. I think that a 10% decline is a huge success, and a testament to the growth of interest in Python and it’s surrounding ecosystem.

From an organizational point of view, PyCon is continuing its tradition of being a mostly volunteer organized conference. It this respect it is a tour de force, at least in the space of open source conferences. PyCon is using a production company to assist, just as ApacheCon is, but the on site footprint of that company is much smaller than the on site footprint of the company for ApacheCon. Moreover, the number of volunteers helping with things is just enormous. Session chairs, runners to escort speakers from the green room to their sessions, a web site builder, lightning talk coordinator, open spaces coordinator, greeters at the conference desk, photographers, and I’m sure there are a bunch more people whose roles I didn’t even get to hear about. Absent a fancy lighted stage display for keynotes, production value wise, I feel that PyCon is operating at the same level of quality as any of the O’Reilly conferences. The program was excellent – tutorials, keynotes, invited talks, regular talks, open spaces, and lightning talks.

PyCon 2009

With PyCon, the Python community is getting way more mileage out of its face to face time than any other open source community. The combination of lightning talks, open space, and sprints creates a powerful feedback loop within the conference proper, which then extends into the sprint days. This dynamic has evolved over the years as PyCon attendees have come to understand the role of these vehicles. Here’s how it works:

PyCon 2009

The lightning talks allow anyone, regardless of stature, influence, or reputation to get in front of the entire conference. People now recognize that some of the most interesting, surprising, and entertaining moments of PyCon take place during the lightning talks. It’s a measure of the influence of the lightning talks that even the 8AM morning lightning talk sessions were well attended. At other conferences the morning sessions are reserved for keynote presentations by paying sponsors. I usually skip these because the content value is low. But I definitely got up to make sure that I hit those 8AM lightning talks. If you’ve gotten in front of the community with a lightning talk, you can extend your reach by scheduling an open space session.

PyCon 2009

Above is a shot of the open space board for Saturday. Note that the time slots go from 10AM to 10PM. There were a few prank type sessions, but for the most part, that board really is full all day long with 10 rooms available during each one hour time slot. Consider that there were 4 ballrooms for the talks, and that the talks went from 10:20AM till 5PM. There was way more air time in the open space sessions, and people certainly made use of it. This is why PyCon is a working conference – it’s not only about transfer of information, real work gets done there.

PyCon 2009

The only tricky thing with open space is that it would be great to have electronic access to the contents of the open space board during the conference. That would help make the open spaces a first class citizen in the minds of attendees. This is an interesting problem, because part of the value of the open space is the physical board, so turning it all electronic wouldn’t be a good idea. I wonder if Kaliya Hamlin has an experience with this sort of thing.

Used well, the open space sessions are great for organizing your little (or big) slice of the world wide Python community. They are also great as a prelude to a sprint once the conference has finshed. And as I’ve already mentioned, the sprints are a great time to reinforce a project’s community as well as move it forward.

PyCon 2009

All of this notwithstanding, the PyCon organizers are not sitting on their laurels. They keep on looking for ways to improve the conference. The buckets you see above are an example of this. Instead of paper or electronic surveys, attendees were asked to vote for talks by taking a red chip and tossing it a bucket on their way out the door. Green for good, yellow for ‘meh’, and red for bad. This is way less effort than the surveys, and I observed a decent number of people putting in their chips. Doug Napoleone has more on the origins of this system, as well as a pointer to the raw data on the results.   

Twitter is now in the mainstream at PyCon. Guido mentioned Twitter during his keynote, and used it to ask questions during the conference. One of James Tauber’s first slides told people which hashtag to use when covering his talk. I’d guess that I got at least 20 new followers each day of PyCon, and I think that I might even be trained to use hashtags now. #pycon was in the top 10 Twitter during the days of the conference. The takeway is that if you are going to a conference and you are not on twitter, you are missing out. The corollary is that if you are a conference, and you aren’t making use of twitter, you need to pay attention. Ian Skerrett has an interesting post on how they used Twitter during EclipseCon. One thing that was missing was a video display of the search for #pycon. I know from talking with Doug Napoleone that he has some wonderful ideas for taking all the social networking stuff to the next level. I’m really looking forward to seeing that next year.

Photography

I’ve been to a lot of conferences over the last few years, always with a camera in hand. At each conference I shoot less and less. There are now lots of people swarming around with cameras, and I feel a bit done out with shots of people speaking from the front of a room, rows of white male attendees listening to a talk, and the rest of the usual conference shots. The same thing happpend with me and liveblogging conferences. Also, it’s hard to do the hallway track and do decent photography.   Last year, the PyCon organizers asked me to take some official pictures, which I was happy to do. This year they didn’t (which was fine by me), but I had planned to bring the camera anyway, because PyCon is PyCon, and photographing there is one way that I try to give back to the community.

It turns out that the organizers were way more organized about photography this year. They actually had someone to coordinate the photography for the conference. Steven Wilcox had a last minute emergency and couldn’t make it. I found out about all of this just a half an hour before I left for the airport. Steven had planned to do headshots of Pythonistas, and was planning to get studio lighting equipment and so on. All of that was now up in the air. Since I had done a bunch of headshots of ASF people at ApacheCon, I tossed some Strobist lighting gear into my suitcase, just in case. By the time I landed in O’Hare, Erich Heine had stepped up to replace Steven, and I joined the “Python Paparazzi” or “pyparazzi”, along with Erich, Jason Samsa, Dan Ryder, and Stéphane Jolicoeur-Fidelia.

PyCon 2009

Since PyCon was in Chicago last year, I was familiar with the Crowne Plaza Hotel, which is a decent hotel, but nothing to write home about. This year the conference proper moved to the Hyatt Regency down the street. PyCon has a tradition of trying to keep costs low in order to keep the conference accessible to the community, so I was expecting something like the Crowne Plaza. I couldn’t have been more wrong. The Hyatt is a photographer’s paradise. There are lots of interesting colors, textures, and some areas with beautiful overhead natural light. If you were going to photograph a wedding, you would die for settings like these for the bridal portraits.

PyCon 2009

This tiled inset in wall turned into the backdrop for James Tauber’s headshot.

James Tauber

It doesn’t have to be strobe(ist) to be a good headshot!

PyCon 2009

This orange lit panel behind a bench seat turned into the backdrop for Jim Baker’s headshot.

Jim Baker

In addition to the pyparazzi, there were plenty of other cameras floating around the conference. Andy Smith decided to do a photographic project called the “Beards of Python“. When this set was announced on Flickr, it caused some Twitter buzzing amongst some of the female attendees of the conference. One thing about photographers is that we (or at least I) are always willing to take some interesting photos. So when the Twitter buzzing reached me, I offered to photograph any interested Geek Girls. James Duncan Davidson and I have discussed the value of trying to photograph female attendees at technology conferences. Since our photographs are often used for advertising, this can be a way of helping women feel more comfortable about attending — knowing that there will be other women there can be a help. So not only did I get to shoot more pictures of interesting people, I hope that in some small way this will contribute to making PyCon friendlier to women.

Catherine Devlin

This is Catherine Devlin, a contributor to sqlpython. Go read her post “Five minutes at PyCon change everything” for an actual example of the lightning talk/open space/sprint scenario that I described above.

The entire set of Pythonista headshots, as well as the rest of my conference coverage are up on Flickr. Who knows what we’ll come up with for next year in Atlanta…

Travel

Regular readers will know that a trip to PyCon traditionally involves some kind of travel mishap. This year was pretty minor compared to previous years.   United lost my luggage for the flight from Seattle to O’Hare, despite the fact that I arrived 2.5 hours early, and checked in at the “Premier” checkin line. I got my bag the next day, so it wasn’t really that bad. Maybe next year will be the PyCon with no travel glitches.