Another shortcoming of this initial multi-GPU implementation is the limited program support. While NVIDIA's driver requires setting an environmental variable for most programs before their SLI technology will be initialized, this allows Scalable Link Interface to be used on most any OpenGL program. The ATI Linux driver relies upon auto-detection of the program's name to determine whether to use CrossFire and that support is currently limited to Doom 3, Quake 4, and Enemy Territory: Quake Wars. When attempting to trick the driver into using CrossFire for other OpenGL programs by faking their program name, we were faced by problems. Hopefully we will see an option for ATI support on other OpenGL programs in the future (of course, we would like to see CrossFire on Unigine, Lightsmark, SPECViewPerf, and even Nexuiz for some of the lower-end cards).