Here you go: https://developer.apple.com/library/content/documentation/MacOSX/Conceptual/BPSystemStartup/Chapters/CreatingXPCServices.html https://developer.app

Here you go: https://developer.apple.com/library/content/documentation/MacOSX/Conceptual/BPSystemStartup/Chapters/CreatingXPCServices.html https://developer.apple.com/library/content/documentation/Ma... It is higher level, though, it is not something you would integrate into the kernel (like bus1 intends to be). OSX has decent IPC though, since it is based on the Mach research kernel from CMU, which was kind of based around the concept of messaging to begin with. Applescript has interesting IPC concepts as well.