Don't know how many people know this yet but Id software has released the source code for Quake3
http://www.fileplanet.com/dl.aspx?/plan ... source.zip
I am using this to write my entity loader (so i can load directly from BSP)
if i get working build i will post it, but if someone wants to try to make one before i do, please go ahead as i probally don't have enough C++ skill yet to do that task.
::BEWARE::
There is ASM coding in there. As Carmac said on slashdot, you should delete the ASM code and just use the C implementations instead.