Jelathnia
Cyan gradually open-sourced portions of the game (or did they open all of it? I don't remember that detail) and once again ran their own server with the ongoing help of donations. Currently that official shard coexists with user-run shards.
At the time Ryzom Core was open sourced (in full, mind you) Cyan had only committed to releasing the client source code and at the time had promised to do so for something like a year but had yet to deliver. They finally delivered the client and tools an some scripting code. Still no 3D assets or server-side code.