grid.org was a website and online community established in 2001 that focuses on cluster computing and grid computing software for users. For the first 6 years of its history it operated several different volunteer computing projects that allowed members to donate their spare computer cycles to worthwhile causes. More recently, it has been relaunched as a community for open source cluster and grid computing software. The website now points to the UniCluster website.
Read more about Grid.org: Open Source Grid Community, Past Volunteer Computing Projects