There's msx, but I don't think it's as matured as jsx (but I've never run into any issues using it)

Thanks!

Why is it not as popular though? In theory, wouldn't building off mithril be a better foundation than react? (speaking in terms of community commitment and third party libraries which mithril somewhat lacks.)

I bet you have some great talent though: an eye for detail & a more logical mindset, no?

Don't sweat it, if you feel so intimidated, create an anonymous github account and just do it (granted you are actually trying to contribute). Check here for some guidelines: https://github.com/blog/1184-contributing-guidelines