That's not nearly the advantage you think it is. For many of these APIs, it's going to be just as easy to have a portable implementation of the pthread's or soc

That's not nearly the advantage you think it is. For many of these APIs, it's going to be just as easy to have a portable implementation of the pthread's or socket API itself. Simply wrapping an API, but otherwise exposing it as-is (which basically everyone does for threads & sockets) does not gain you any portability whatsoever.