I wrote the initial version of the IRC gateway myself during a train trip, and while I considered connecting it directly to our Redis message queue, it’s actually simply using our API. Hence, you could actually write a similar gateway yourself.
To help similar projects get started, we’re now open-sourcing the IRC gateway (Oulu on GitHub). It’s a simple Ruby app, using EventMachine, and it does a custom implementation of the IRC protocol. The name Oulu of course refers to the Finnish city where IRC was originally invented.
Whether you want to add features to Oulu, fork it as your own XMPP gateway, or simply like hacking something on your own, let us know. Our 100 Beer Ventures Fund even likes to reward active developers in our ecosystem!