Interesting - this is new to me (and ironic, given Aether was a candidate name for Matrix!). The projects seem very similar in some ways - both python/twisted/sqlite server stacks + angular frontend. The big differences seem to be that Aether is using AMP as its federation protocol rather than Matrix's HTTP/JSON federated DAGs, and is focused initially on forums rather than IM/VoIP. It's a bit strange that it advertises itself as entirely peer-to-peer though, when seemingly it is very much a client-server model (with server/server federation) just like Matrix, SMTP or XMPP. It's also slightly strange that the github repo is only showing certain drops from a private repo - I wonder why the dev isn't happening in the open. It's also hard to see what the actual decentralisation algorithm is, beyond replication. It doesn't seem to be using DAGs for eventual consistency or signing forum history.

In terms of anti-spam proof-of-work stuff, identity, sybil attacks and all the good stuff mentioned at http://blog.getaether.net/post/101566226287/a-few-updates-ab... it sounds like Aether & Matrix are at a fairly similar point. It would be super-cool to chat to Burak and get the two federated together (after all, Matrix is all about being glue between other communication media) - will ping him :)