I use Trac at work. Trac is one of the best things I discovered after we started practising Agile Methodologies. Its as if trac was written with Agile Teams in mind.
We use it write XP User stories, User Acceptance tests, file bug tickets and maintain To Do Lists, Technical Glossary and some times we even capture the whiteboard discussions with a mobile camera and post it as a wiki page, so that the discussion is available for reference. With Trac, we are able to capture all the artefacts of the XP cycle. Its amazing how useful the Trac Wiki is proving to be. I especially like the Todo Lists.
A lot of newly hatched Open Source Projects use trac.
Newsforge is carrying a good piece on Project Management with Trac.
Oh! by the way, Trac is written in Python :)
© 2003-2011 Pradeep Gowda