As an experiment we have gotten an instance of Zulip running for Python's development at https://python.zulipchat.com (IOW this is for discussing the development of Python only). As Guido has put it you can view Zulip like "hyper-interactive email" as we have streams corresponding to equivalent mailing lists and all messages fall under a topic so conversations are on-topic.

The instance is currently rather open at the suggestion of Zulip, so people can create new streams, add bots, etc. There are already bots I have added for commit notifications, Travis failures, and deployments of Bedevere and The Knights Who Say Ni.

The invite message when you sign up mentions all this, the CoC, etc., so do give it a read. Otherwise feel free to join and help us decide if this is useful enough to make a permanent thing for Python's development!