This bundle for Symfony2 (built upon HWIOAuthBundle) allows to be the client of an oauth SSO server (especially an SSO server with several "authspaces").
Learn how to use the bundle with the documentation.
Want to built your own SSO server (with multiple "authspaces")? Take a look at the DaOAuthServerBundle!
Want to communicate from API to API or from Client to API? Take a look at the DaApiClientBundle!