Google Apps will support the OAuth protocol.

Google announced support for the OAuth authentication protocol for users of its online office suite, Google Apps. OAuth was chosen because it provides a sufficiently high level of security for users.

Using the OAuth protocol, Google Apps users and administrators can provide external applications with keys to access the APIs of various Google Apps applications. This means users won't need to enter their login and password each time they access Google Apps system functions.

The OAuth protocol architecture allows users to access protected user resources without having to transmit their login and password.

OAuth was first introduced in November 2006 and was used for Twitter. The OpenID and OAuth protocols have much in common, but OAuth is a separate project.