[ara4n]

This would be a really cool use for Matrix - the eventual consistency and offline operation stuff is a perfect fit :D

You don't need an email address to sign up currently - the way it works is that it's up to the homeserver to decide how to validate new users (if at all). So Matrix.org uses a CAPTCHA to check you're human, but otherwise just sends a username & password. We also let you optionally specify a mail address, mainly just to prove that we do support validating 3rd party IDs like email (and in future MSISDNs and other IDs).

For gatewaying, the main thing we've been missing is an Application Service (AS) API on Matrix which lets your gateway masquerade multiple users & rooms/channels from the remote protocol. Currently you can write a back-to-back bot which creates, per user, an IRC user on the IRC network and a Matrix user on the Matrix network and bridges them together - this is how the current Matrix<->IRC bridge works. This sucks if you want to easily project hundreds of users & channels from IRC into Matrix and vice versa, though - you need better server support, a bit like IRC Services' architecture.

The good news is that this is very nearly implemented - we got our first AS up and running a few hours ago (it currently just logs traffic rather than bridging it anywhere). It's all happening on the application-services branch of https://github.com/matrix-org/synapse and the doc is at https://github.com/matrix-org/matrix-doc/blob/application-se... and https://github.com/matrix-org/matrix-doc/blob/as-http-api/dr... if you're interested.

Twisted is probably overkill for many ASes, but it could be a great way to do the XMPP & IRC bridging in future.