Glow

 glow  (last post 2011-07-12 advises using G+) supported integrations with Twitter and Facebook and a complete stack of federated social web protocols and standards (activitystrea.ms, poco, pubsubhubub, salmon, etc.).

Glow is currently limited to glow.io subdomains if you want to try it out. At some point it will likely be opened it up to any host/domain.

Folks that were using it on their own site:
 * Darren Bounds (http://dbounds.glow.io/profile (connection has timed out), author of glow)

Other instances / earlier work:
 * http://ooava.com/ (domain abandoned) was a personal project social node for publishing (photos, videos, status updates) and conversation on the web and Android. ooava was a personal site that evolved into the glow project.