Paint by Numbers  
   Offers two color puzzles available to print out or solve online.
   http://www.blindchicken.com/~ali/games/puzzles.html

Elite Japan Crossword  
   Downloadable software for solving paint by numbers puzzles in many formats, including plain black and white bitmap files. Also has a solving tutorial.
   http://www.griddlers.com/

Solving Paint-by-Numbers Puzzles with Integer Programming  
   Article and instructions on solving puzzles.
   http://www.oberlin.edu/math/faculty/bosch/pbn-page.html

Conceptis Puzzles  
   Creator and supplier of picture-forming logic puzzles. Contains online games and those for sale from Japan.
   http://www.conceptispuzzles.com/

The Jcwd  
   The programs for creating and solving Japanese crosswords.
   http://www.catchysoft.com/