+The [[!cpan LWPx::ParanoidAgent]] perl module is used if available, for
+added security. Finally, the [[!cpan Crypt::SSLeay]] perl module is needed
+to support users entering "https" OpenID urls.
+
+This plugin has a configuration option. You can set `--openidsignup`
+to the url of a third-party site where users can sign up for an OpenID. If
+it's set, the signin page will link to that site.
+
+This plugin supports the
+[myopenid.com affiliate program](http://myopenid.com/affiliate),
+which can be used to help users sign up for an OpenID and log into your
+site in a single, unified process. When you create the affiliate, specify a
+login url like `http://example.com/ikiwiki.cgi?do=continue`. Once the
+affiliate is created, set `openidsignup` to point to the affiliate's signup
+url.
+
+This plugin is enabled by default, but can be turned off if you want to
+only use some other form of authentication, such as [[passwordauth]].