EyeOS, an open source Web operating system
Web operating systems are essentially personal productivity environments implemented using Web browsers, AJAX, and other Rich Internet Application technologies with data and additional services being provided by a Web server.
There are only a handful of Web operating systems that are reasonably stable, few that approach mature, and even fewer that are open source. Fitting all of these categories is eyeOS, an open source Web operating system written in PHP.
When you download eyeOS you have the choice of two windows implementations: The MiniServer or the MicroServer.