I have everything I need to use XGL, and xorg.conf is configured correctly, but when I try to start it via startxgl I get this:
 couldn't create glitz screen drawable for window Fatal server error: no screens found
Xorg.93.log reveals no errors, other than the usual crap about not being able to aquire AGP DMA.
Aren't you trying Xgl with Via Unichrome integrated graphics card?
I think Xgl doesn't work with Via Unichrome now :-( Maybe in future...
I'd heard that it does... :? Ah well, I'll try AIGLX then, and see if I can get that working.