I would like to allow users to log in into my website with OpenID. So far I have integrated Google and Yahoo.
What other popular services are offering OpenID login
Here are some OpenId endpoints :
These following services are not OpenId providers and have their own authentication flow :
take a look what stackoverflow is offering.
https://stackoverflow.com/users/login
sadly no idea what urls you have to use, but a little choice what is popular so far.
regards
check out SocialAuth or JOpenId for some cool java-based APIs
Well if you allow the user to input their own openID url then they can use ANY endpoint. That's the whole point of openID: if you support one endpoint, you support them all. Like StackOverflow, it is best to cover a number of the most popular endpoints so that inputting the openID url is easier (for example, most people don't know the Google OpenID url even if they have an account). You should definitely cover Yahoo, WordPress, Blogger, AOL and MyOpenId like this. But if people like me, who have their own personalised openID url come to your site, they should have the option to use that one.
The OpenID specification actually requires that you provide the URL input box. The input element should also have the OpenID logo as the background image.
Actually, it shouldn't matter since the user will supply you with the URL to ask. All OpenID providers work the same way, so the URL should be all you need (see http://openid.net/)