nanomsg is trademarked by the inventor of the protocols. (He does seem to take a fairly loose stance with enforcement though -- since he advocates using names that are derived from nanomsg, as long as its clear that there is only one "nanomsg".)
I'm pleased to announce that this past weekend I released the first version of my implementation of the SP (scalability protocols, sometimes known by their reference implementation, nanomsg) implemented in pure Go. This allows them to be used even on platforms where cgo is not present. It may be possible to use them in playground (I've not tried yet!)
About two years ago Joyent began offering Linux instances, running under KVM, stored on ZFS, and secured by Zones (“double hull virtualization”). Since then, I’ve been doing more and more work on Linux performance as customers deploy on these instances. It’s been fascinating to work on both the illumos and Linux kernels at the same time (a Linux guest in an illumos host), with full stack visibility of the guests, and hypervisor, down to metal.