It is still in the small program stage although Glitch as a C# framework is usable now (indeed, I've written an editor, UI, and so on, all very concurrent). As a framework, it is not really convenient without being a new language, but it could be interesting to do something like ReactJS using replay and rollback.

If you like Bret Victor-style demos, I'm working on a web essay that should be done sometime this summer.