Direct Rendering Infrastructure

Abbreviated by: DRI.

DRI is a framework that allows processes to safely and efficiently access graphic hardware.

X (via mesa ?) installs DRI if the graphic card supports it.

Apparently, a user must be member of the video group to be able to access graphic hardware acceleration.

Checking if DRI is enabled

grep DRI /varlog/Xorg.0.log

should print something like (II) intel(0): direct rendering: DRI2 enabled

Alternatively, if glxinfo is installed, the following grep can be used:

glxinfo | grep -B2 'direct rendering'

It should print

name of display: :0
display: :0 screen: 0
direct rendering: Yes

Finally, the working of DRI can be confirmed with

glxinfo | egrep ' OpenGL (vendor|renderer|version)'

If this egrep does not print something like Software Rasterizer, then the user who ran this command has working acceleration.