So I thought, this morning, "I'll add a gem to http://manabasecrafter.com to act as an OpenID server." But all the gems are obsolete. Then I thought "Didn't I use something called MyOpenID at one point?" They've closed. Then I thought "Didn't Google offer one?" They discontinued it last month. Then I thought "I'll do it the dumb way and just use the WordPress plugin that does it on a dummy site." That plugin is no longer supported and incompatible with the current version of WordPress. Then I thought "I'll try it in raw PHP." There is apparently one working library, and all they offer is an example server "to give you an idea of how to write your own implementation."