Best 3d Accel Open Source Driver Card?
 

I have been looking through the HCL but cannot find much information on what I want to know.
I would like to buy a new video card that has good support for DRI under Linux. Specifically, I would like the drivers to be open source, or at least available in source format, so I can compile them myself and do not have to rely on the companies precompiled binaries. I don't care if I have to recompile X or anything.
Does anyone have any suggestions as to what I should look into?
Thanks
Guy