Shareware:
ChessExplorer
PROGRAM FOR CHESS PROBLEMS
by Jan Nowakowski
From the site:
"ChessExplorer is a Windows software (Win32) with full graphics interface, principally designed to solving orthodox chess problems: direct mates, selfmates, helpmates.
It has some additional options:
creator of problems ( "Mate in 2" and "Mate in 3" )
solving tasks of the kind "8-Queens Problem"
counting number of possible continuations from the given position.
Generally, ChessExplorer is created to test all possible moves and to find exactly all solutions that exists (mode "brute force" - using big force of modern computers).
This principle isn’t violate by added some "bits of intelligence" (for exemple, a side who defends to mate, "remembers" his good, already verified moves, and he doesn’t need test every time all posible moves).
This software is realized in C++. The basic procedures was optimized in assembly language and the program tests more than 1,000,000 moves per second (sometimes more than 10,000,000 m/sec) on a standard computer."
http://www.geocities.com/explorer127pl/
For chess problem enthusiasts ! Check it out !