<li><b>dri</b> - Meta state tracker for DRI drivers
<li><b>glx</b> - Meta state tracker for GLX
<li><b>vdpau</b> - VDPAU state tracker
- <li><b>vega</b> - OpenVG 1.x state tracker
<li><b>wgl</b> -
<li><b>xorg</b> - Meta state tracker for Xorg video drivers
<li><b>xvmc</b> - XvMC state tracker