Portier - An email-based, passwordless authentication service that you can host yourself.
yiid - yiid - Your Internet Identity - Simplify your community life
OpenID - OpenID is a safe, faster and easier way to log in to web sites.
Profilactic - Profilactic.com is an online identity aggregator that pulls together all of the profiles and...
IndieAuth - IndieAuth is a way to use your own domain name to sign in to websites.
humanID - humanID is a one-click anonymous SSO that provides users with an anonymous identity layer.