Languages: English and Russian
Compatibility: INTEL ONLY!! XP, Vista, and 7 [If I'm not mistaken.]
Author's Description:

Most of you know what Linpack is I guess. In case you don't, it's a benchmark designed to measure performance on Intel CPUs in GFlops. But it's also a very useful tool for checking the stability of a CPU.

My Opinion: This program has always proved as a great stability test when I do not want to use Prime95. This bench REALLY works your processor in order to find any instability.
Author's Page & Downloads: English Page Russian Page