common public license (cpl1.0) source for two command line

solvers has been posted at

http://www.research.att.com/sw/download/tgz/ast-sudoku.2006-01-24.tgz

even though it is open source there is a license handshake

for rationale see

http://www.research.att.com/sw/download/faq.license.html

sudoku is a 9x9 technique based solver

I stopped coding new techniques at x-cycles (~simple coloring)

sudocoup is an NxN sudoku/QWH (latin square) solver coded for speed

its a backtrack solver, but solves most 9x9 sudoku without backtracking

using a 1 level forward check

for a refreshing change neither solver employs dancing links