List of sites with two factor auth support which includes SMS, email, phone calls, hardware, and software.
Simple and Lightweight Auth System for CodeIgniter
The boss of http auth.
Auth hook for Iron-Route
More than just a user database auth package for FuelPHP
Auth module for Lift using MongoDB
Auth manager for Yii2
Sails.js Email/Social Auth full template to make it super easy to start a new project