http://www.prakinf.tu-ilmenau.de/~hirsch/Projects/Squeak/Sokoban/

>From the change set:

"The game was apparently invented in the early 1980s by 
Thinking Rabbit, a computer games company in the town of 
Takarazuka, Japan. The game design is said to have won 
first prize in a computer games contest. Because of the 
simplicity and elegance of the rules, and the intellectually 
challenging complexity of the composed problems, Sokoban 
quickly became a popular pastime. The object of Sokoban is 
to push all stones (or boxes) in a maze, such as the one to 
the right, to the designated goal areas. The player controls 
the man and the man can only push stones and only one at a time. 
The restriction of only being able to push the stones makes 
this game challenging: One can create unsolvable positions. 
Players will soon learn that this is the main obstacle in 
solving problems. Advanced players also try to find shorter 
and shorter solutions, measured in stone pushes and man moves." 
(From http://www.cs.ualberta.ca/~games/Sokoban/) 

Enjoy,
-Robert