@Sebastian Great! in case Zygmunt doesn't answer, as per Freenode policy it's possible to reclaim the channel for an official open source project - although it requires action on @Jermolene part, so let's first see if this Zygmunt reacts.
I'm curious to see how the dat and ipfs projects will evolve, but honestly I'm also still waiting for someone to write a WebRTC syncer for TW. (@ldorigo The only way right now is with Bob or Tiddlyserver)
Depending on what you're after, it does support the normal TW authentication mechanism (via HTTP basic) and I guess you could always put a webserver in front like people have been doing with IIS or nginx under linux.
@BurningTreeC Yes. https://dat-tiddlywiki.glitch.me/ is a multi user environment where everyone can watch and authorized browsers (?) can edit. There is like an individual key that must be copied to a list by an editor. I did just a short test. Edits in browser 1 were reflected in browser 2 almost instantly. Unauthorized users can edit their own copy but not save back to the source.