Henry Casson's Crossword Utility - Enables a crossword grid to be entered and converted to and from a text encoding which can be emailed. Freeware. [Windows] - http://home.freeuk.net/dharrison/puzzles/utility.htm
EclipseCrossword - Creates crosswords and puzzles, includes project ideas, examples, tutorials and international applets. - http://www.greeneclipse.com/eclipsecrossword/
Across and Across Lite - Literate Systems' crossword display and construction software. [Windows, MacOS, Linux] - http://www.litsoft.com/across/preview.htm