Has anyone successfully gotten Beryl/Xgl to run on an 64-bit Fedora installation? I have an nVidia 6600.

No, but I've gotten close this afternoon, on FC6, X86_64, nVidia GeForce 6150 le (on motherboard). My mouse pointer tends to disappear and leave droppings about. I don't think I'm using Xgl. I installed nVidia's version of their driver rather than an rpm.

i do have make work the beryl with XGL but it work a bit slow than using the AIXGL or the NVIdIA rendering. Now i have a Geforce 7900 Gs.... another think its if u install the Nvidia drivers from livna... ok so far but if u install the official ones u need to do several changes over the xorg.conf and i mean more than just:
" nv to nvidia "
on the "device" section u most add this lines:
Option "TripleBuffer" "true"
Option "AllowGLXWithComposite" "True"
Option "RenderAccel" "True"
Option "AddARGBGLXVisuals" "True"
Option "DisableGLXRootClipping" "True"
i think the most important one its the second and third one.

PS: almost forgot ye my pc its an (x86_64) amd

Yes, it works: follow that link: http://nicofo.tuxfamily.org/dotclear...eryl-on-fedora
It's a script that installs XGL on your Fedora (and it detects the architecture 32 or 64 bits).

It will work with your nVidia card, but normally you do not need XGL: nVidia drivers contains everything necessary for the 3D-desktop.