Official site

• http://trac.edgewall.org/

Comments:

• Quick, flexible and customisable. The Bitten continuous integration plugin (http://bitten.edgewall.org/) works really well for Python projects too.
• Doesn't work as well for projects that don't use SVN. We use Git and we ended up having to replace it with a Git-web plugin of our own invention

Start-ups using:

• WebMynd
• GroupSpaces
• Smarkets
• CogniDox