Free and open source Java Sudoku
Version: 2.3 BetaJudoku is a free and open source Java implementation of Sudoku. Visually attractive, interactive version of Sudoku with intelligent and brute force solving strategies.
Operating System: Mac OS X
You can select one of the predefined puzzles and make the applet solve it.
Alternatively, you can clear the playing field and use your mouse to copy one of your own puzzles, then see it getting solved.
Press your mouse button repeatedly to enter a value between 1-9 or clear the cell. You can also use the 0-9 keys and the cursor keys to navigate.
Do notice the 'Optimization' options and the slider on the right that can be used to speed up the solving process.
More importantly, this special Java applet allows you to store (save) and later restore (load) your (possibly partially solved) puzzles :)