What's wrong with bouncers? ZNC has been serving me well over 5 networks for years now. I don't see the appeal in an in-browser solution at all.
Isn't this what Quassel http://www.quassel-irc.org/ does, or am I misunderstanding what you're asking?
I really want an IRC kernel with an API, so I can have all sorts of clients on different machines/platforms, but it seems to be impossible at the moment, without using the horrible bouncers.