I wasn't sure where to put this in "Gameplay Changing" or "Non-Gameplay Changing".
Basically my story was or is -> for some time I was playing with various IDTech3 engines, even created my own project based on Wolfenstein: Enemy Territory (GPL v3 code).
For several days I have been working with Tremulous engine and updated it with most of stuff what I already did on GPL v3 based codebase, and because I was author of it, I can re-license my updated to any license what I want, so it can be used in Tremulous.
I have chosen little different path. I am not modder or map maker, so I cannot show you better models or graphics (no matter if I am using XreaL renderer engine), so I based all my work on engine stuff, not game logic (cgame, ui and game - all work on that is based on rev. 2260), so in next few days I can present you stable working developer snapshot of engine (both x86 and x86-64 client). Also I will not show you list of features what I added or supported, but will show you in dev. snapshot.