OAuth is an open protocol, initiated by Blaine Cook and Chris Messina, to allow secure API authorization in a simple and standard method for desktop, mobile and web applications. For consumer developers, OAuth is a method to publish and interact with protected data. For service provider developers, OAuth gives users access to their data while protecting their account credentials. In other words, OAuth allows a user to grant access to their information on one site (the Service Provider), to another site (called Consumer), without sharing all of his or her identity.
OAuth Core 1.0
OpenID Single Sign On and OAuth Data Access for Google Apps (Google I/O 2010)
OAuth @ Google Code