Player-run site for all things North American Scrabble. If you're interested in playing in a tournament, start here. Also, I did a volunteer design project for the site! My designs will be implemented soon!
Internet Scrabble Club (ISC)
Online server for playing Scrabble against people all over the world, as well as AI of varying skill levels. ISC is where I discovered the competitive Scrabble scene.
Mind Sports Academy
Mind Sports International is a games startup hoping to capitalize on large-scale board+card game / eSports events based on their parent company's poker events model. This is their most up-to-date site, currently endorsed by both Hasbro and Mattel.
Hasbro-endorsed organization for North American Scrabble.
Mattel-endorsed organization for international Scrabble.
There are also country-specific associations around the world. Typically a Google search of [country] + Scrabble will return the organization for which you're likely searching!
Fun study tool for learning the dictionary through "word walls" of alphagrams. Gets my #1 vote for best available study tool, albeit only usable on desktop right now.
Breaking The Game / Words of Wisdom
Scrabble's version of Doyle Brunson's Super System. Written by one of my Scrabble mentors and legends of the game, Kenji Matsumoto.
Windows-only (sadly) Scrabble AI that focuses more on inference and defense than Quackle. Has lots of potential but has not been recently updated.
Word-searching site boasting a robust search tool and a variety of preset word lists. Works for both US and Int’l dictionaries, as well as Words with Friends.
The Scrabble AI that revolutionized the way people learn the game.
Another great homegrown study tool from Chris Lipe. Best option for mobile studying.
Third link down. Only comes with the international lexicon. If you're set on studying the "OWL 3" (American lexicon) and need a copy of the lexicon, feel free to send me an email. Or just use Aerolith.