I was surfing for some ticketing / project management software and it returned the following result:

• Sifter

• Beanstalk

• Redmine

• Unfuddle

• Lighthouse

• JIRA

• 16 bugs

• Bugzilla

• Fogbugz

• Trac

Especially Sifter looks really nice! But… it isn’t open source. So too bad. I went with Redmine: open source, ruby on rails and already a nice feature set!

A nice overview of bug/issue tracking systems can be found on wikipedia.