Git wasn't released until 2005, so what did they use before then? I know it says they pulled the history from 24 snapshots.
I guess the part from before SCCS was still meticulously reconstructed?
Edit: this doesn't actually answer your question of where unix used to live, rather than linux though....
No - BitKeeper revoked the free license because some guy (unrelated to Linux) wrote a client that reverse engineered more features than BitKeeper liked.
And Linux actually used BitKeeper only between 2002 and 2005; prior to that time, it did not use a source control system at all.