Simple compared to what? The Go implementation is very immature, I'll grant you that, but it is definitely more complex than an implementation of C at a similar point in its life. At the very least Go supports, fairly straight forwardly, a lot of C and it has a GC and multiplexing user land threads over multiple cores.

* Assume C90

Ahh, if we are comparing equivalent implementations, you are definitely correct. GC and goroutines are much more complex than anything in C. In fact, off the top of my head, the only features truly missing in Go from C are unions (unfortunately) and the preprocessor (effectively a part of C).

Have you ever implemented GC or fibers? They can be pretty simple to implement, really.

There is a big difference between implementing them for fun and implementing them for a production system. Regardless, even if they are simple to implement they are more than what C90 has so, by definition, more complex implementation.

They're a lot simpler than printf, strxfrm, or mktime, all of which are in C90!

They are conceptually more high level than anything in C - that's what I meant.