Below are the technical specifications for OpenSocial, gadgets, and the REST/RPC protocols. Check out the specification process used to evolve these specs.
OpenSocial 2.0 Working draft
View entire draft in SVN
OpenSocial 1.1 New!
View entire draft in SVN
OpenSocial 1.0
View entire draft in svn
Archives
OpenSocial v0.9
View entire spec in svn
OpenSocial v0.8.1
Other resources
OpenSocial (v0.8)
OpenSocial (v0.7)