Open source social network framework Elgg (like WordPress for Facebooks) is now supported by social media client app Seesmic, according to an announcement on the Seesmic blog this morning. With the addition of the Elgg plug-in, Seesmic users can now view and update multiple Elgg networks in the same interface they use for Twitter, Facebook, Ning and numerous others. That's good news for Seesmic, which is in a very competitive market.

Elgg is good for groups interested in creating niche networks under their own control, either publicly or privately. The service can run on your own servers or through a hosted version just launched last Summer. It came from the Education world and is used today by various organizations including Oxfam, Hill & Knowlton PR, the Australian government and the state of Ohio. Seesmic is a Salesforce-backed social network meta-service, allowing users to interact with multiple networks on multiple platforms.

Open source social networking is good for the web and for the world because it advances user and community freedom and helps mitigate the power of social network behemoths. Support for open source social networks by proprietary software like Seesmic is great for everyone and helps enrich the usefulness of those networks and the software used to build them.

Neither of Seesmic's leading competitors, Tweetdeck and Hootsuite, appear to support Elgg to date.

Leading social business analyst firm Altimeter published a research report last month about this sector of apps, which it calls social media management systems. That report identified 28 leading vendors. Altimeter's Jeremiah Owyang writes about the market:

"Social Media Management Systems... which help companies manage, maintain, and measure thousands of social media accounts, [and] are the next growth market for the social business category. While saturation is at 58% of corporate buyers, the average deal size is a meager $22,000 but will expect to grow to six figure annual deals in coming quarters to meet market demand.

White label social networks, like Elgg, are plentiful as well. ReadWriteWeb has done two in-depth interviews with Elgg co-founder David Tosh over the past 4 years. Tosh is now "experimenting" on a stealth project called Bluejac.

Below, a screenshot of an Elgg community accessed via Seesmic.