HoDoKu - HoDoKu is a sudoku helper written in Java and available in English and German.
Yasminoku - Sudoku game and solver totally written in DHTML.
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.
Get Sudoku - Get Sudoku is an interactive sudoku solver.
Sum Fun - A fun number puzzle game for iPhone and iPad.