If you are working on web/AJAX based user interfaces, you owe it to yourself to go and check out the Windmill web testing framework/tool. Windmill was originally developed at OSAF for testing the very AJAXy web front end of Chandler Server. Adam Christian and Mikeal Rogers, the core developers of Windmill, have gone on to other efforts, but Windmill lives on. In fact, this summer, Adam was fortunate enough to land a job where he is able to spend significant amounts of time working on Windmill. That effort has paid off with the latest version of Windmill, which should be ready for serious use. It’s got a bunch of cool features, including nice integration with Firebug Lite.