OpenID free WordPress plugin

OpenID is an open standard that allows users to authenticate to websites without having to create a new password. This plugin allows users to login to their local WordPress account using an OpenID, as well as enabling commenters to leave authenticated comments with OpenID. The plugin also includes an OpenID provider, enabling users to login to OpenID-enabled sites using their own personal WordPress account. XRDS-Simple is required for the OpenID Provider and some features of the OpenID Consumer. Developer documentation, which includes all of the public methods and hooks for integrating with and extending the plugin, can be found here.