After reading Ender's journey into XreaL at
http://obliter8.com/node/768 I did a little more research on this because It got me interested, and I found that:
"XreaL will be a non-commercial multiplayer only first person shooter based on a heavily modified Quake 3 Arena engine (id Tech 3). The aim is to push the rendering technology until it can be compared with current commercial titles and then to produce a playable Total Conversion. Quake 3 Arena’s gameplay will be only slightly modified. The simpleness of the original game will stay but the game media will be replaced completely with high quality assets that match the new engine’s technology."
This was taken from
http://xreal.sourceforge.net/wordpress/?page_id=2
It looks like this project needs help from people like TRaK, since they are looking for artists at
http://blenderartists.org/forum/showthread.php?t=75255
The date from this goes to 19-Aug-06, but I googled a little more and I found that some guy made it work at
http://starbase-12.blogspot.com/2006/06/quake-3-source-xreal_18.html if you want to check out his screenies. I also posted some screenshots in the galleries.
I hope Ender can make something with this, because it would make Tremulous look awesome! Keep the good work!