» Asymmetrical Sudoku
   Includes a generator and solver.
   http://sudoku.netgubbi.dk/

» Bob Hanson's Sudoku Assistant
   JavaScript-based gameboard and solver. Can use cross-hatch scanning and subset elimination.
   http://www.stolaf.edu/people/hansonr/sudoku/

» BrainBashers
   Offers daily puzzle in one of three difficulty levels. Archive of daily puzzles and an assistant.
   http://www.brainbashers.com/sudoku.asp

» Braingle Sudoku
   Interactive sudoku game with high score tracking. Includes solution strategies.
   http://www.braingle.com/games/sudoku/index.php

» Count to Nine
   Offers five difficulty levels, timer, solution, and printable view.
   http://www.counttonine.com/

» Daily Sudoku Puzzle
   Offers daily timed puzzle and four difficulty levels. [English/Portuguese/Spanish/German/French/Italian]
   http://www.daily-sudoku-puzzle.com/

» Fiendish Sudoku
   Free daily sudoku puzzles at five difficulty levels. Online solving grid with hints and step-by-step solutions.
   http://www.fiendishsudoku.com/

» Free Sudokus
   Offers hints, solution checking and grids in sizes other than 3x3.
   http://www.free-sudokus.com/

» GSudokr
   Online sudoku puzzles with solutions, game instructions, and timing.
   http://www.gsudokr.com/

» Goobix.com
   Offers up to four difficulty levels.
   http://www.goobix.com/games/sudoku/

» Jaap Scherphuis' Generator
   Java-based generator offers four levels of difficulty. Includes view of solution.
   http://www.geocities.com/jaapsch/sudoku.htm

» Number Logic
   Offers a new timed game daily, with a validator and four difficulty levels.
   http://www.number-logic.com

» Paul's Pages
   Offers random, crafted, and non-standard puzzles. Includes hints and import/export tool.
   http://www.paulspages.co.uk/sudoku/

» Play Sudoku
   Registered users can save unsolved puzzles and high scores are kept at three difficulty levels. Also offers rules and tips for solving. [English/Russian/German]
   http://www.play-sudoku.de/

» Ridiculopathy - Sudoku Shuffle
   Play with letters or numbers in the grid. Includes high scores, hints and move verification. [Requires Flash]
   http://www.ridiculopathy.com/crappy_flash_games.php?gamename=sudoku

» Seeing With C - Sudoku Solver
   A solver program with an article explaining the algorithm used.
   http://www.seeingwithc.org/sudoku/sudoku.html

» Su-Doku.net
   Offers daily puzzle, downloadable games, and instructions.
   http://www.su-doku.net/

» Sudoku Central
   Offers daily puzzle for printing. Also includes archive, online solver, and solving tips.
   http://www.sudokucentral.com/

» Sudoku Fun Puzzles
   A website representation of Sudoku, the broad sheet newspaper puzzle imported from Japan. Leaderboard lets players compare completion times.
   http://www.sudokufun.com/

» Sudoku Hints
   Offers daily web-based puzzles with five difficulty levels. Includes solver, helper, and XML feed.
   http://www.sudokuhints.com/

» Sudoku League
   League of online competitors. Scoreboard, rules, FAQ, hall of fame, and instructions. [English/Czech]
   http://www.sudoku-league.com/

» Sudoku Puzzles
   Daily puzzles offered at four difficulty levels, available for play online or printed out. Includes rules and archives.
   http://sudoku.com.au/

» Sudoku Zone
   Play sudoku puzzles online for free.
   http://sudoku-zone.50webs.com

» Sudoku by Froggy
   Generates 2x2, 3x3, and 5x5 puzzles with adjustable level of difficulty.
   http://www.orcapia.com/froggy/sudoku/

» SudokuDave
   Easy to very difficult puzzles that you can play online or print out.
   http://www.geocities.com/da5id65536/SudokuDave/

» Web Sudoku
   Free puzzles with difficulty levels ranging from easy to evil. Provides print and online syndication.
   http://www.websudoku.com/

» s.udok.us
   A new Sudoku puzzle every day and an archive of old grids.
   http://s.udok.us