"Velruse is a set of authentication routines that provide a unified way to have a website user authenticate to a variety of different identity providers and/or a variety of different authentication schemes.

It is similar in some ways to RPXnow with the exception of being open-source, locally installable, and easily pluggable for custom identity providers and authentication schemes.

You can run Velruse as a stand-alone service for use with your websites regardless of the language they're written in. While Velruse itself is written in Python, since it can interact with your website purely via HTTP POST's."