Offers problems and solutions.

Solve online puzzles.

(Freeware, Unix/Windows , source code) CHEST solves non-trivial orthodox mate problems, selfmates, helpmates, and stalemates. Fairy chess is not supported.

Freeware program that helps to compose, to solve and to store endgames studies and chess problems with FEN, EPD and PGN formats. It converts Windows programs that admit these formats in graphical interfaces for Crafty, Popeye and Chest.

Solves orthodox proof game problems.

Windows program for solving chess problems - Mates, Self Mates, Helpmates

[Shareware] Mate solver for Win95/Win98/WinNT.

(Freeware, DOS, source code) Solves orthodox direct mates, emphasizes clear code at expense of speed.

(Freeware, 386+, DOS/Linux) Solves retrograde problems.

(Freeware, Unix/DOS, source available) You enter a (fairy-) chess-position and a stipulation, Popeye tries to solve this (fairy-) chess position.

(Freeware, PC) Problemiste is a freeware program entirely dedicated to the chess problem: Solves orthodox chess problems: direct mates, helpmates, selfmates from 2 up to 6 moves, Writes and prints the solutions with many options, Prints diagrams using your Truetype fonts, Manages archives which can contain thousands of problems.

(freeware) program for composing and solving fairy chess problems by Vaclav Kotesovec. In Czech.

[ Commercial-200 Euros] Solves chess/fairychess problems with up to 20 stipulations, 100 aims, 700 fairy pieces, 500 fairy conditions.