HoDoKu - HoDoKu is a sudoku helper written in Java and available in English and German.
Sudoku369 - The twist of Sudoku with the magic of 369
Simple Sudoku - Freeware Sudoku Puzzle Maker and Solver
Web Sudoku - Web Sudoku is an Exciting Math Puzzle, Board, Free to Play, Online, and brain challenging video gameplay on a 9*9 Sudoku board.
nsudoku - A Sudoku game made with ncurses.
Sudoku Portable - Sudoku Portable is a an addictive puzzle game originally created in France over 100 years ago.