OpenSocial was a "standards-based component model for cloud based social apps" formerly at http://opensocial.org/ which now redirects (along with all URLs at that domain) to a W3C blog post: http://www.w3.org/blog/2014/12/opensocial-foundation-moves-standards-work-to-w3c-social-web-activity/
OpenSocial closed and gave everything to W3C.
OpenSocial was discussed at the 2013 W3C Social Web workshop.
- Out of date: https://www.quora.com/Is-OpenSocial-dead
- Cites "Orkut" which died previously to OpenSocial closing
- http://opensocial.org/ (now redirects to W3C blog post)
- https://opensocial.atlassian.net/wiki/display/OS/Home - wiki appears up but out of date?