Earlier quoted context omitted.
You can either follow my guide [1] based on updated cross-gnu scripts, or try out gnuxc [2] for bootstrapping a full Hurd distribution, with the caveat that it requires your host to be Fedora. [1] http://blog.darknedgy.net/technology/2015/07/25/0/ [2] https://github.com/dm0-/gnuxc
I found this bit in your post interesting: "kdbus (which was called “neutered Mach IPC” by Neal Walfield)" - does that mean mach ipc provides typed interface registration / binding between userland processes? I admit, I know very little about mach and thought it was for kernel/user-space communication only (both directions)
Yes, practically all Mach subsystems other than virtual memory have ports implicitly created for them. This includes tasks (address spaces) and threads (units of CPU time), which together form processes.