Links to other good Sokoban sites:
Uncle Chuck's Solutions to 379 Sokoban Puzzles
Solutions to the 50 levels included with Sokoban++ (some are different), and many others
Spanish Sokoban site, includes links to many Sokoban clones for many platforms
List of Sokoban clones and solvers
Sokoban forum
3D OpenGL Sokoban for Windows.
Run Sokoban on a MS SQL server.
Another online playable version, written in Macromedia Flash
Use at your own risk!
YASC (Yet Another Sokoban Clone)
Brian Damgaard's well-known Sokoban clone.
This is also one of the famous versions of Sokoban (not free anymore, but shareware)
This site also includes a very complete list of Sokoban links
Two sites of Games 4 Brains SokoFun, a shareware Sokoban clone from germany
The Sokoban implementation for Windows with the best mouse control of all. Site also includes a Hexoban implementation (Sokoban on a hexogonal grid).
Links to not Sokoban-related sites:
Some more small games made by me
Sokoban++ related:
Download this game at Tucows (4/5 cows rating)
Download Sokoban++ from one of their servers
This is the German Sokoban++ website.
Homepage of one of the Spanish translators
Homepage of the Italian translator
Download extra skins for Sokoban++ from Taggeriam.