CVSTrac

The TracHistory states that CVSTrac was the original source of inspiration for Trac.

Indeed, CVSTrac was certainly the first system to integrate browsing of a VersioningSystemBackend (originally CVS), a BugTrackingSystem and a Wiki.

CVSTrac was created by D. Richard Hipp, who is also the author of the embeddable SQL database, SQLite.

See CVSTrac in action for SQLite and for CvsTrac itself.

Update: while CVSTrac is still live, it seems that drh is working on a new generation of this software, called Fossil. See e.g. the Timeline. The nice thing here is that this CVSTrac / Trac clone is not only using a distributed version control system, it is a DVCS... Interesting stuff for #1465.