TypeJS

[cgarciae]

As promised, here is a link to the type checking system I suggested: https://github.com/cgarciae/TypeJS

It has a decent documentation. The implementation is not commented. It's on it's own repo, shall we merge it or use it as a dependency?

[DrBoolean]

That looks fantastic!

I think using it as a dependency is great for now. Let's type this thing!

[KiaraGrouwstra]

TypeScript and Sanctuary have also done type checking (compile-time vs. run-time, respectively), and have had quite some momentum -- the former in its adoption by Angular 2, the latter in considerations to have Ramda-Fantasy merged into it. Might those perhaps be considerations? Disclaimer: I've only taken a short glance at TypeJS.