There's some interesting things going on behind the scenes here. Some of this will find it's way back to shindig.
In any case it's a generalized solution for calling JSON-RPC endpoints with postMessage flow using OAuth2.
Originally shared by Mano Marks
Pretty cool, a new way to access many of Google's APIs, though not Maps at the moment. In particular, Google+, Freebase, Contacts, Latitude, and a host of other APIs. And it'll handle the authentication for you.
Very nice! Going to dig through their postmessage code, that's always the painful part.
Jakob Heuser, Dec 01 2011 on 1500wordmtu.com