Plan 9 is a pleasure to program in. You need to make a service available transparently over the network? Talk the 9P protocol. Need to access a service over the network? Talk the 9P protocol. Need to talk locally to one of those services? Talk the 9P protocol. How do you talk the 9P protocol? Either use the 9p system calls directly, or use file operations that result in 9P.
The variant of C is a well considered update to the standard, unlike C++.
Namespaces are constructed on the fly. You bin is in one place and is a union of all the executables your process needs to see. So no path environment variables. Stuff really is simpler in Plan 9. It's very productive if you write programs to use yourself. I do.