This is an unofficial distribution for SIS 1.3. SIS is a logic synthesis package developed at the University of California at Berkeley which allows interactive optimization of sequential digital circuits.
SIS 1.3 is a somewhat modified version of SIS 1.2. The most important changes are a general code reorganization to use autoconf/automake as a build system, and some portability issues fixed. SIS 1.3 should build out-of-the-box on modern Linux, OSX and Windows (with Cygwin) machines.
SIS is obsolete. MVSIS is a successor to SIS which is currently being developed and maintained. I strongly encourage people to use MVSIS where they can instead.