Credits

Sudoku Fun owes a great deal to these sites and projects:

• SudokuWikisudokuwiki.orgTechnique theory and how to explain it
• Kazusa Sudokusudoku.kazusa.techTechnique system and theory tutorials
• HoDoKuhodoku.sourceforge.netTechnique families and difficulty
• Sudoku Explainersourceforge.net/projects/sudoku-explainer · skfrgithub.com/dobrichev/skfrER difficulty ratings
• sudoku.coachsudoku.coachHint and interaction design
• SudokuPadsudokupad.app · f-puzzlesf-puzzles.com · Logic Masterslogic-masters.deVariant puzzles and link import
• YZF SudokuOur earlier solving engine
• Alex Kubiesa OCR ModuleOur earlier OCR engine

And thanks to every player who sent us ideas. Happy solving.