As the spec says, the ID service is optional. We haven't even bothered speccing it because the current logically-centralised thing is placeholder until we find a good decentralised solution. "Strong identity system" simply refers to mandating public key infrastructure both for servers and clients. For servers it's implemented via perspectives as per http://matrix.org/docs/spec/#retrieving-server-keys. For clients it's currently being defined for our new E2E stuff; we'll publish the key management APIs over the next few weeks.
I'm afraid I do believe that XMPP has failed in providing a ubiquitous (i.e. as ubiquitous as the web or email) open federated ecosystem for realtime comms, otherwise we wouldn't have tried to build Matrix. Obviously we may fail too, but hey, might as well try. Sorry if you consider this opinion trolling :)
In terms of "only the baseline counts" or "MUC is fragmented", I'm either mis-communicating or you're misunderstanding. I do think XMPP suffers from too low a baseline of functionality (as do others on this thread seemingly), and I think that the various alternative group chat technologies on XMPP (e.g. MUC v FMUC v Buddycloud) between them cause fragmentation, in that conversations can get stuck in one protocol inaccessible to another (please correct me if I'm wrong).
And yes, Matrix models multi-user chat as 'simply' a distributed datastructure replicated over multiple servers with eventual consistency, using decentralised ACLs to maintain authority in the chat.
I'm afraid I do believe that XMPP has failed in providing a ubiquitous (i.e. as ubiquitous as the web or email) open federated ecosystem for realtime comms, otherwise we wouldn't have tried to build Matrix. Obviously we may fail too, but hey, might as well try. Sorry if you consider this opinion trolling :)
In terms of "only the baseline counts" or "MUC is fragmented", I'm either mis-communicating or you're misunderstanding. I do think XMPP suffers from too low a baseline of functionality (as do others on this thread seemingly), and I think that the various alternative group chat technologies on XMPP (e.g. MUC v FMUC v Buddycloud) between them cause fragmentation, in that conversations can get stuck in one protocol inaccessible to another (please correct me if I'm wrong).
And yes, Matrix models multi-user chat as 'simply' a distributed datastructure replicated over multiple servers with eventual consistency, using decentralised ACLs to maintain authority in the chat.