Looking for an open source CMS?

Try this site: opensourcecms.com. This is what the web is about (Web 2.0 and semantic Web aside): a site that includes full installations of several dozen open source content management systems and blogging, ecommerce, groupware, elearning, and wiki platforms, and then some. I've used this site extensively while comparing features of different open source CMSs - it gives you an admin login to each one and refreshes each installation every two hours to undo all your experimenting. Great site.