cube.tar.gz is the source for s Rubik's cube
solving program written by Dik T. Winter <Dik.Winter@cwi.nl>.
It is distributed under the MIT license. See license.txt
for details.

optimal.tar.gz is the source for a Rubik's cube
solving program written by Michael Reid
<reid@math.ucf.edu>. It is distributed under the GPL. 
See license.txt for details.

solver.tar.gzis the source for a Rubik's cube
solving program written by Eric Dietz 
<root@wrongway.org>.  It is distributed under the GPL.
http://wrongway.org/?rubiksource