"You might lose the fun in solving Sudoku puzzles but I certainly had fun writing this HTML5 app."
Run directly on GitHub: http://richardeigenmann.github.io/Sudoku/
Testing: Runs OK on Chrome and Firefox for Linux as well as Chrome for Android Not running on XP with old IE.
Description: This app draws a Sudoku grid and allows the user to pick the numbers she wants to place in the grid. As each number is picked the options that are no longer possible are removed. If a number is "forced" because it is the only one that can take that place in the row, colum or grid then it is highlighted. The steps and puzzle can be saved by clicking the save button. To reload a saved puzzle drag the saved file over the list of steps.
Wikipedia on Sudoku: http://en.wikipedia.org/wiki/Sudoku Scientific American on Sudoku: http://www.cs.virginia.edu/~robins/The_Science_Behind_SudoKu.pdf
Motivation: In Switzerland, where I live, Sudoku is so pupular that the free newspapers have two puzzles in every edition. I and my partner sometimes like to compete against each other solving them. I usually need to copy out the puzzle to a larger piece of paper so that I have enough space to write down the numbers that are possible and do the exclusion logic. I have long felt that I should be able to do this on the computer so here it is. I do admit, it does take the challenge out of solving the puzzles and the sense of achievement is not the same.
About the author: Richard Eigenmann is an Open Source Software hobbyist who works as a Project Manager / Business Analyst at a bank for a living.