anyway, if I were to assume that you actually understood the architecture of the web platform, I could explain to you how to do that in the following way (although **this will probably not help you until you understand**): on the backend, Google exposes the basic XMPP protocol using a simplified SPDY wrapper, and authenticates you in using your federated Google credentials (OpenID I believe);
it then makes async requests with XHR back and forth to the SPDY<->XMPP proxy to send and receive chat messages. it keeps the socket open and uses SPDY to push updates from the server to the client wh…