Any sudoku fans out there? Did you have some sudokus, that you wasn't able to complete? Here is the solution - a program that solves the sudokus for you. ;)
Actually that was a fun project. To calculate the puzzle, without using brute force. Et voilà! This calculator can find the solution of the simple sudoku, with some kind of heuristic or uses the brute force, for the complicated one.
You can try the demo here.
Or get it on the github. (Open Source. Do what you want with it.)
It is possible to add mode methods to solve the puzzles if you need them.
It is also possible to add more game fields, like samurai-sudoku or nanominosudoku. Or redesign the game field and add more colours. The data format is quite simple.