[[Mach]] is a first-generation [[microkernel]]. Mach's basic abstractions include [[AddressSpace]]s in the form of [[Mach/Task]]s, execution contexts in the form of threads, [[Mach/IPC]], [[capabilities]] in the form of [[Mach/Ports]], and [[Mach/MemoryObjects]], which enable Mach's [[Mach/ExternalPagerMechanism]]. # Documentation - OSF's [Kernel Interface](ftp://ftp.cs.cmu.edu/afs/cs/project/mach/public/doc/osf/kernel_interface.ps) - OSF's [Kernel Principles](ftp://ftp.cs.cmu.edu/afs/cs/project/mach/public/doc/osf/kernel_principles.ps)