I am trying to find a customizable PHP-based SSO server which I can use as a central user administration point for about 20 different websites. Does anyone know of an existing platform I could use or anything that would give me an idea on where to go to build my own solution. Thanks.
Have found a decent one which can be modified to suite a sites needs. Google Jansey SSO and you will find it and it has support not just for PHP based authentication but also has a module for AJAX authentication for non-PHP enabled sites.