Moodle users, you may want to have as look at this comparison of Moodle, Claroline and Atutor. I am familiar with all three systems though not yet in use for teaching. Although this piece comes from the Atutor site, it was not written by them; however, they have picked it up for a reason - it recommends Atutor in preference to the other two. The article is dated 2003 and doesn't make it clear what versions it is referring to. I think that is great that we have multiple opensource VLEs to choose from. I just think you have to be clear on what you need and how best to go about getting it. http://www.atutor.ca/atutor/files/VLE_comparison.pdf

Becta (British Educational Communications and Technology Agency) released in Feb 2004 a report entitled Using ICT to share the tools of the teaching trade A report on Open Source Teaching. It is concerened with the relationship between learning objects, open source software and teaching. It is a 40 page PDF which you can download from their web site at http://www.becta.org.uk

For those of us who believe that the open source ethos and community are important as an educational model as well as a source of free software, I would direct you to Professor Lawrence Lessig's new book published at no cost to the reader in a variety of electronic formats. Its title is Free Culture: How big media uses technology and the law to lock down culture and control creativity. It can be obtained from http://free-culture.org