Libxxf86dga provides the xfree86-dga extension, which allows direct graphics access to a framebuffer-like region, and also allows relative mouse reporting, et al. it is mainly used by games and emulators for games.

more information about x.org can be found at:

this module can be found at git://anongit.freedesktop.org/git/xorg/lib/libxxf86dga