[babo]

Not really. As the intro of this article says, it's possible to disable GC, but you loose most of the libraries, which is one of the strengths of Nim.

[Tiberium]

It can, ARC is really not a full-blown GC (people usually associate GC with a tracing garbage collector which ARC is not). ARC is fully suitable for writing any low-level stuff such as OSes and similar.