I've also had good experience with Trac. If you need sophisticated traditional bug tracking features, it isn't quite all there: you can't assign a bug to more

I've also had good experience with Trac. If you need sophisticated traditional bug tracking features, it isn't quite all there: you can't assign a bug to more than one version, or more than one component, for example. But its subversion and wiki integration are features I can no longer live without.