The Ed Techie: The VLE/LMS is dead
Harold Jarche » Selecting Social Network Platforms
Describes several smaller social network platforms with some pluses and minuses, including Ning, Grou.ps, Buddy Press, and Elgg.
Seven sexiest alternatives to Ning
Alternatives for free online groups now that Ning is shooting themselves in the foot with a paid model
Phil Bradley's weblog: Alternatives to Ning
Tools to create online communities, all probably benefiting from Ning's decision to move to exclusively paid sites