If you want to play these niche modes with a stable player base, v161201 is the latest version that guarantees compatibility.
For the average player, the official Steam version is superior. But for the archivist, the nostalgia-seeker, or the international server admin, is precisely what the keyword promises: a stable, feature-rich, and linguistically complete snapshot of GMod’s prime. If you want to play these niche modes
Some developers and archivists keep old GMod builds for historical research or legacy addon support. These are , but you can find discussions about them on: or the international server admin