From Sudopedia, the free Sudoku reference guide

From Sudopedia

Ruud is the founder of this Sudopedia and has written most of the articles it contains.

He is also the author of the SudoCue software, which is supported from sudocue.net.

He has created the Clueless, Hanidoku and Sukaku variants.

He is co-administrator of the Sudoku Programmers forum.

He is a moderator on the Sudoku Discussions forum.

He publishes the highly appraised Daily Nightmare on his website.

He publishes the popular Solving Guide on his website.

He has no problems showing off a little...