Peter Norvig
Re: Solving Every Sudoku Puzzle -
"Thanks to the pointer.  People who want a very efficient Sudoku solver should indeed look at the dancing links algorithm, and other methods of implementing the all-different constraint in CSP.  But for this article, I was going for the simplest reasonable method, not the most efficient.  I'll have an article coming out in Code Quarterly soon that goes into more detail on efficiency; it is paired with an article covering dancing links." - Peter Norvig