All with lots of implementations both server and client. All more or less ignored. Before suggesting we need new systems you pretty much have to figure out what isn't working with the ones we have ... and real stuff, not unlikely technical reasons that no one cares about ... and no, it isn't just bad user interfaces. People will overcome any user interface if they actually care enough.
Skype took off originally because it was easy to use, even if it didn't always work well. I still think we need better/new software.
So what about the new thing: Matrix? What do we need to do there to make it so it does not fall into obscurity like everything else?
