I wasn’t aware of the fact that there are Open Source drivers for ATI r300 chip available with the standard X.Org release, but they are as you can read at the project page. And acording to the AIGLX page these do work together with AIGLX in contrast to the closed source drivers – actually even the open r400 drivers are supposed to work.
However the question if how the performance is – not to mention the features like TV out. Phoronix made a comparison and lists detailed results. And it must be said that the open drivers do suck compared to the closed source ones – the performance differs by a factor of two.
However, it must also be said that the drivers work, and do support 3D activities – although the driver project is not supported by ATI in any way. And the factor of two may be crucial for gamers, but maybe not so much for desktop users who want to enjoy AIGLX – something which is still impossible with the closed source drivers.
Maybe I will give the free drivers a try when Fedora Core 6 is launched – together with AIGLX. But there is also still hope that ATI is releasing AIGLX capable drivers sometime soon, so maybe I can compare both on my system, too. We’ll see.