Open Source Bug Tracking for Visual SourceSafe?

rfsayre asks: "My employer has been looking into bug tracking options for use with Microsoft Visual SourceSafe, and while I don't have the authority or the resolve to encourage migration from the various MS tools that are in use, I would like to see an Open Source bug tracking system used, instead of Visual Intercept from Elsinore Technologies. Mainly I'm concerned that my employer will try to go as cheap as possible, and I think providing access to everyone from developers to QA interns could get expensive. Of course, what good is bug tracking if not everyone has access to it? So please, show me some Open Source alternatives that talk to SourceSafe, preferably with web based access."