OpenID Wiki

Description
OpenID is an open, decentralized, free framework for user-centric digital identity.

To login to an OpenID-enabled website (even one you've never been to before), just type your OpenID URI. The website will then redirect you to your OpenID Provider to login using whatever credentials it requires. Once authenticated, your OpenID provider will send you back to the website with the necessary credentials to log you in. By using Strong Authentication where needed, the OpenID Framework can be used for all types of transactions, both extending the use of pure single-sign-on as well as the sensitivity of data shared.