I am going to be writing a bit more about NetBSD in the next months.
I applied for 3 different projects for this years Google Summer of Code at NetBSD, and the one for system(3) and popen(3) (and more) to use posix_spawn(3) got accepted:
Nikita Gillmann Make system(3) and popen(3) use posix_spawn(3) internally The library functions popen(3) and system(3) are used to create a new shell process and (in case of popen(3) set up IPC channels to the new process). Currently they are implemented using fork(2), execve(2) and do a bit of astonishing complex internal bookkeeping. It should be possible to simplify both implementations using posix_spawn(3) and associated helper functions. Mentors Jörg Sonnenberger Martin Husemann Riastradh
There's the announcement on the TNF Blog:
I've got something else GSoC related I'm looking into to maybe write about later.