HoDoKu - HoDoKu is a sudoku helper written in Java and available in English and German.
NumberDrop - A uniquely challenging math puzzle game.
Simple Sudoku - Freeware Sudoku Puzzle Maker and Solver
Yasminoku - Sudoku game and solver totally written in DHTML.
Sum Fun - A fun number puzzle game for iPhone and iPad.
USB Sudoku - A very small program for playing the original game of Sudoku.