Why OpenID?
It's a single username and password that allows you to log in to any OpenID-enabled site.
It works on thousands of websites.
It's an open standard.
What is OpenID?
“
OpenID allows you to use an existing identity to sign in to multiple websites, without needing to create new passwords.
You may choose to associate information with your OpenID that can be shared with the websites you visit, such as a name or email address. With OpenID, you control how much of that information is shared with the websites you visit.
With OpenID, your password is only given to your identity provider, and that provider then confirms your identity to the websites you visit. Other than your provider, no website ever sees your password, so you don’t need to worry about an unscrupulous or insecure website compromising your identity.
OpenID is rapidly gaining adoption on the web, with over one billion OpenID enabled user accounts and over 50,000 websites accepting OpenID for logins. Several large organizations either issue or accept OpenIDs, including Google, Facebook, Yahoo!, Microsoft, AOL, MySpace, Sears, Universal Music Group, France Telecom, Novell, Sun, Telecom Italia, and many more.
Who Owns or Controls OpenID?
OpenID was created in the summer of 2005 by an open source community trying to solve a problem that was not easily solved by other existing identity technologies. As such, OpenID is decentralized and not owned by anyone, nor should it be. Today, anyone can choose to use an OpenID or become an OpenID Provider for free without having to register or be approved by any organization.
The OpenID Foundation was formed to assist the open source model by providing a legal entity to be the steward for the community by providing needed infrastructure and generally helping to promote and support expanded adoption of OpenID.
”http://openid.net/get-an-openid/what-is-openid/
if you want more about openid,you can visit http://openid.net.
What is my Google OpenID URL? （转自：http://lists.openid.net/pipermail/openid-general/2009-July/009271.html）
Google expects you to use the "Directed Identity" feature to sign in
with your Google account. Enter into the box the following string:
https://www.google.com/accounts/o8/id
...and you should end up logged in as a URL at google.com with a
humongous string of hexadecimal gibberish on the end of it. That URL is
your Google OpenID URL.
This will only work if bitbucket.org supports OpenID 2.0.