[noedig]

I was thinking the same thing. When is something just a library, and when is it something more? Think about concurrency in Go. Goroutines are cool, but what makes them more than just a cooperative threading library? Channels? Those are just concurrent data structures. The special sauce in Go is the select structure. It allows you to easily express control flow that cannot be expressed without select (or at least not easily). What is the special sauce in these probabilistic programming languages? What could not be implemented using a library?