A really good place to start is their Switch Systems entry here. They are lacking their own accessible games section so hopefully someone (maybe me) will take up the gauntlet for that soon.
"GATE is actually a Wiki, which is a piece of server software that allows users to freely create and edit Web page content using any Web browser. It's a little like Wikipedia, but just concentrating on assistive technology. GATE is very simple to use, with a control panel enabling you to add content and more. More about Wikis . . .
This wiki has been created by AbilityNet, the UK's largest provider of advice and information on all aspects of Access to technology. The purpose of the wiki is to provide live and up to date information on all aspects of Assistive Technology."