You'll find there is a shed load of OAuth2 provider libraries, look at "server libraries" here: http://oauth.net/2/

Also, a few that aren't listed: Rails: https://github.com/pelle/oauth-plugin Django: http://code.larlet.fr/django-oauth-plus/wiki/Home NodeJS: https://github.com/nightworld/node-oauth2-server (me) CakePHP: https://github.com/thomseddon/cakephp-oauth-server (me again)