HyperSAT is a research SAT solver written to experiment with B-cubing search space pruning (see Publications for more details).

HyperSAT is not actively developed. Due to low-level bit hacks it is limited to 32-bit machines. The solver has been extensively tested. However, unless you are interested in the guts of B-cubing or HyperSAT performs particularly well on your instances, I’d recommend that you use the Spear, which inherits some features from HyperSAT and is incomparably faster.

Release 1.7 source (Mar 2005) [tar.bz2].