All software development organizations, take notice: Atlassian builds software right and the result is continually great software. I can't speak for Crowd (haven't used it), but I certainly know that the process defined in this article certainly will put your project on the path for success (in terms of technology... of course if the idea sucks, a nice dev process won't save you!):

Basically we have taken the following steps:

1. Move from CVS to SVN
2. Move from Ant to Maven 2
3. Add some level of test coverage, and build this into our development process
4. Add integration tests for the Crowd Console
5. Hook all this up with Cargo and Maven 2
6. Drop it into a continuous integration server

(Via Atlassian Developer Blog.)

The only thing I think they could improve on is the use of JWebUnit/HtmlUnit. They should really step up to Selenium, especially considering how often bugs crop up due to inconsistencies across web browsers. But still, that is merely an incremental improvement to their very solid foundationl. On top of that, JWebUnit has an abstraction layer on top of Selenium, so it should be an easy switch.