It's going to be open-sourced at some point, just not now.

What I meant is I'm building an alternative client that gives people a lot more freedom. For example, you can use XMPP as your primary messenger, and still communicate with your teammates via Slack.

You can also have access to all your history and a much, much better instant search.

In the future, an IRC/XMPP gateway will be built in as well.