Personal choice but indeed Trac is very nice and is still used by high profile projects like Django (especially supporting ticket triage) and Twisted Matrix.
Indeed fossil-scm [1], has same interface as Trac (in my view partly inspired by it). Have used Trac for a long time, so can't complain, it works well, its simple and flexible.
I mean, if we're counting Trac as the same, despite the drastically different UI and project-first rather than code-first focus, then we also need to count Sourceforge, which was open source in its first (2000) and third (2009) incarnations.
Yes, that's when it was included to Trac 1.0 as a built-in plugin. Before that, it was a 3rd party plugin you have to install yourself. I remember using it before 2010 and I'm pretty sure the plugin pre-dates github.
