I'm one of the knockout core developers. Just a heads up, knockout 3.5 just went into beta, and 4.0 is in alpha.

I spoke the other day with another core developer, Ryan Niemeyer, and he noted that ko is still a good fit for quick and lightweight dynamics, but with good conventions a solid foundation for really complex Web apps. It's still very solid, and the API largely unchanged since IE6 was around.

Tko, the monorepo for ko 4+, will hopefully make it easier to build frameworks out of the knockout code, so things like routers can be easier to tack on (if we don't build one in).

Incidentally I've just set up a patreon for tko/ko 4 in particular at patreon.com/brianmhunt- it'd be great to be able to have more time to hack at it.