Hashiwokakero

Back to the asian games... And now we present to you... Hashiwokakero is played on a rectangular grid with no standard size, although the grid itself is not usually drawn. Some cells start out with (usually encircled) numbers from 1 to 8 inclusive; these are the islands. The rest of the cells are empty.
The goal is to connect all of the islands into a single connected group by drawing a series of bridges between the islands. The bridges must follow the criteria below:
They must begin and end at distinct islands, traveling in a straight line in between
They must not cross any other bridges or islands
They may only up/down or across
At most two bridges connect a pair of islands
The number of bridges connected to each island must match the number on that island
Solving a Hashiwokakero puzzle is a matter of procedural force: having determined where a bridge must be placed, placing it there can eliminate other possible places for bridges, forcing the placement of another bridge, and so on.
Here are some key features of "Hashiwokakero":
· Create new puzzles manually or automatically; automatic creation offers puzzles with different grid sizes from 7x7 to 25x25
· Solve existing puzzles manually or let program solve it
· Save puzzles as bitmap files
· Print puzzles and solutions
· Display options include: circular or square islands, island size and display color schemes
· Puzzle size limitation of 7x7 to a maximum 25 rows and 25 columns
· 20,000 puzzles with varying levels of difficulty and solutions are provided.