Sudoku and Killer variants

• Ed Pegg Jr. (Math Games)
• Wei-Hwa Huang
• Jean-Christophe Godart
• 1st Sudoku World Championship (instruction booklet)
• 2nd Sudoku World Championship (instruction booklet)
• Miyuki Misawa
• Yahopogroup: Sudoku World
• Hexapuzzle
• Brainfreeze Puzzles

Battleship variants

• Fathom It! (battleship variants)

Misc Puzzles

• Cihan Altay (PQRST)
• Vladimir Portugalov
• Janko.at
• Age of Puzzles
• The Griddle
• Perplexus (3D Sudoku)
• Steve Schaefer (Cube Sudoku)
• Michael Z. R. Gottlieb
• Hanidoku
• Diceboard (KiMo variants)
• Hexafex
• Reiner Knizia
• Oleg Andrushko
• enriching mathematics (search for sudoku on this page)
• The Sudoku Club
• Peter Sudoku
• Colour Sudoku
• Sudoku Guy Blog
• The Poly Pages (Polyomino Sudoku Problems)
• Bob's Squiggly Sudoku (Jigsaw sudoku)
• Victor W. Marek
• minidoku
• Sudoku 1 (polish)
• Sudoku Evolution
• sudoku.com (variant forum)
• djape.net (variant forum, see also the killer forum there for many killer variants)