[[!meta copyright="Copyright © 2002, 2003, 2007, 2010 Free Software Foundation, Inc."]] [[!meta license="""[[!toggle id="license" text="GFDL 1.2+"]][[!toggleable id="license" text="Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license is included in the section entitled [[GNU Free Documentation License|/fdl]]."]]"""]] [[Mach]] is a first-generation [[microkernel]]. Mach's basic abstractions include [[virtual_address_space]]s in the form of [[task]]s, execution contexts in the form of [[thread]]s, [[IPC]], [[capabilities|capability]] in the form of [[port]]s, and [[memory_object]]s, which enable Mach's [[external_pager_mechanism]]. Controlling [[task]]s, their [[virtual_address_space]], [[thread]]s, and other system objects in Mach is implemented by using [[port]]s, as opposed to other [[kernel]]s' [[system_call]] interface: almost all of the Mach API is implemented by sending [[message]]s to [[port]]s. Device drivers that reside in kernel space are controlled by ports, too. Mach's [[API]] is well-[[documented|documentation]]. [[!toggleable id=mach_kernel_principles text="""[[!template id=note text="*[[mach\_kernel\_principles|documentation]]*: {{$mach#kernel_principles}}"]]"""]] In particular the [[!toggle id=mach_kernel_principles text="[mach\_kernel\_principles]"]] book further elaborates on Mach's concepts and principles. # IRC, freenode, #hurd, 2013-08-26 < stargater> then is mach not more microkernel < stargater> when it have driver inside < braunr> mach is a hybrid < braunr> even without drivers < stargater> in www i read mach is microkernel < stargater> not hybrid < braunr> the word microkernel usually includes hybrids < braunr> true microkernels are also called nanokernels < braunr> the word isn't that important, what matters is that mach does more in kernel than what the microkernel principle implies < braunr> e.g. high level async IPC and high level virtual memory operations < braunr> including physical memory management