[Air-L] Online learning environments

Hello everyone: I've been reading this list for awhile, and this is my first time posting. I'm looking to find information on online learning environments, whether they be connected to universities or standalone, not-for-profit or otherwise. Hoping to collect information on the key players in this space - thought this could be a good resource to turn to. Recently found ConceptArt.org, and am interested in similar community-focused sites combining a mix of tutorials, videos, collaborative tools, job boards, etc. Any insight would be incredibly appreciated. Thank you! Lev Davidson