Canopia Crosswords - A variety of crosswords along with other word games.
ClueMaster - A collection of puzzles available to solve online or download. Fee required.
The Crossword Centre - A resource guide with links, books, software, and a collection of interactive and downloadable puzzles.
Crossword Puzzle Games - Offers thousands of puzzles ranging in size and difficulty. Site also offers a creator and a solver.
Crossword Puzzles - Offers many types of crossword puzzles, creation software, and solving tools.
Crossword Puzzles and Blokkiesraaisels - A collection of various styles of puzzles by Anina Roux, compiled for magazines and newspapers in South Africa.
CrosswordLinks.com - A comprehensive resource with rules and helpful tips, articles, software, forums, and information about leagues, tournaments and online play.
Monograph on Crosswords - An instructional and philosophical essay by an enthusiast. Also gives links.
The New York Times Crosswords & Games - The daily crossword puzzle with four ways to play, plus free classic crosswords and trivia quizzes. Subscription required.