As an actual user of ZeroMQ, nanomsg and dabbler of libdill, I assure you I know what I am talking about. Libdill/libmill is NOT on the same arch. It could be used to implement the next generation of zeromq/nanomsg, but it does not, in fact, provide any functionality that these provide today - it would be an internal implementation detail if sustrik followed through on that comment. But it would not be a nanomsg rewrite, likely something completely new - nanomsg has been rewritten, several times in several ways, by Garret D'amore who has taken over. D'amore explicitly rejected using e.g. libuv (mentioned in that comment) as a basis for a nanomsg rewrite. There's an "uncertainty" principle at work here - separating of concerns generates dependencies which in the grand scheme of things are not necessarily good.

In fact, one of D'amore's rewrites used native OS threads in lieu of a co-routine library, which worked perfectly well on FreeBSD and Solaris, and abysmally on all other OSses. The main reason to use a coroutine library in a messaging library is actually that the underlying OS threads implementations scale so badly on most modern systems.