a general purpose monitoring platform. provides a framework dealing with (among others) packet demultiplexing, timers, threads and communication. This allows programmers to concentrate on the precise functionnalities they want to implement...
a URL based identity system. An OpenID identity is simply a URL, and all the OpenID specification does is provide a way to securely prove that you own that ID on that URL. Unlike most identity systems, OpenID is completely decentralized.