View source for MkLinux

{{short description|Computer operating system}}
{{Infobox OS
|name = MkLinux
|logo = <!-- Filename only -->
|logo caption = 
|screenshot = <!-- Filename only -->
|developer = [[Open Software Foundation|OSF]] Research Institute, [[Apple Inc.|Apple Computer]], MkLinux Developers Association, [[Free software movement|volunteer community]]
|family = [[Macintosh operating systems|Macintosh]], [[Linux]] ([[Unix-like]])
|working state = Discontinued, legacy
|source model = [[Open-source software|Open source]]
|released = {{Start date and age|1996|02}}
|discontinued = Yes
|latest release version = Pre-R2
|latest release date = {{Start date and age|2002|08|05}}
|kernel type = [[Hybrid kernel | Hybrid]]
|license = [[GNU General Public License]]
|marketing target = [[Researcher]]s, [[Hacker culture|hobbyists]]
|programmed in = [[C (programming language)|C]]
|language = English
|language count = 
|package manager = [[RPM Package Manager|RPM]]
|supported platforms = [[PowerPC]]
|userland = [[Red Hat Linux]]
|ui = [[Command-line interface|Console]], [[X11]]
|preceded by = [[Mach (kernel)|Mach]], [[Linux]]
|succeeded by = [[macOS]], [[PureDarwin]], Linux
|website = {{URL|mklinux.org}}
}}

'''MkLinux''' (for '''Microkernel Linux''') was an [[open-source software]] computer [[Computer multitasking|operating system]] begun by the [[Open Software Foundation]] Research Institute<ref name="LinuxonOSFMach3"/> and [[Apple Inc.|Apple Computer]]<ref name="MkLinuxApple"/> in February 1996, to port [[Linux]] to the [[PowerPC]] platform, and [[Macintosh]] computers. The name refers to the [[Linux kernel]] being adapted to run as a server hosted on the [[Mach (kernel)|Mach]] [[microkernel]], version 3.0.<ref name="AppleKernelProgrammingGuide" />

==History==
{{Details|topic=this lineage|macOS|macOS version history}}
MkLinux started as a project sponsored by Apple Computer and OSF Research Institute, to get "Linux on Mach" ported to the Macintosh computer and for Apple to explore alternative kernel technologies on the Mac platform. At the time, there was no officially sponsored PowerPC port of Linux, and none specifically for Macintosh hardware. The OSF Institute, owner of the Mach [[microkernel]] and several other [[Unix]]-based technologies, was interested in promoting Mach on other platforms. Unlike the design of the later [[macOS]] versions 10 and newer (not to be confused with the contemporaneous [[Classic Mac OS|Mac OS]] versions 9 and older), MkLinux was designed to take full advantage of the Mach microkernel.

The effort was spearheaded by Apple's VP of Development Tools [[Ike Nassi]]<ref name="Ike Nassi CHM interview">{{cite interview |last=Nassi |first=Ike |author-link=Ike Nassi |interviewer=[[John Markoff]] |publisher=Computer History Museum |date=August 26, 2016 |type=Video |series=CHM Oral History Collection |id=102717191 |title=Nassi, Ike oral history |url=https://www.computerhistory.org/collections/catalog/102717191 |access-date=February 9, 2019}}</ref> and Brett Halle at Apple, and development was later split between two main people: Michael Burg on device drivers and distribution at Apple in Cupertino, California; and Nick Stephen on Mach porting and development at the OSF in [[Grenoble]], France. Other key individuals to work on the project included François Barbou at OSF, and Vicki Brown and Gilbert Coville at Apple.

MkLinux was officially announced at the 1996 [[World Wide Developers Conference]] (WWDC). A free CD containing a binary distribution of MkLinux was handed out to the attendees.

In mid 1998, the community-led MkLinux Developers Association took over development of the operating system.

The MkLinux distribution was too large for casual users to have downloaded via the slow [[dial-up Internet access]] of the day, even when using 56k modems. However, the official CDs were available in a book from Prime Time Freeware, published in English<ref name="MkLinuxbookEnglish"/> and in Japanese.<ref name="MkLinuxbookJapanese"/> The book covers installation, management, and use of the OS, and serves as a hardcopy manual.

Apple later released the [[Open Firmware]]-based [[Power Macintosh]] computers, an official PowerPC branch of the Linux kernel was created and was spearheaded by the LinuxPPC project.<ref name="HistoryofLinuxforthePPC"/> MkLinux and LinuxPPC developers traded a lot of ideas back and forth as both worked on their own ways of running Linux. [[Debian]] also released a traditional monolithic kernel distribution for PowerPC—as did [[SUSE Linux|SUSE]], and [[Terra Soft Solutions]] with [[Yellow Dog Linux]].

When Apple dropped support for MkLinux, the developer community struggled to improve the Mach kernel, and to support various Power Macintosh models. MkLinux continued to be the only option for Macintosh [[NuBus]] computers until June 2000, when PPC/Linux for NuBus Power Macs was released.

==Reception==
''MacTech'' magazine observed this of the general state of Linux on Macintosh in 1999: "Seen as a Windows NT or commercial Unix killer in some circles, Linux also promises to give the Mac OS a boost in the right direction and might even give Mac OS X Server a run for its money among Apple shops." The installation process was seen as "either smooth as silk or very, very rough" and that it "can also be slightly more difficult to recompile the MkLinux kernel because of the extra steps to placate the Mach microkernel." MkLinux had greater hardware compatibility than LinuxPPC at the time, supporting both NuBus and PCI Macintosh systems whereas LinuxPPC only supports PCI. Compared to LinuxPPC, MkLinux was generally known as having a performance cost due to the overhead of the Mach kernel. The Linux environment was found to provide a potentially adequate desktop suite, but one that forgoes the entire Macintosh experience in favor of pure Linux.<ref name="Linux Gains"/>

===Legacy===
MkLinux is the first official attempt by Apple to support a [[free and open-source software]] project.<ref name="MkLinuxApple"/> The work done with the [[Mach (kernel)|Mach]] 3.0 kernel in MkLinux is said to have been extremely helpful in the initial porting of NeXTSTEP to the Macintosh hardware platform, which would later become macOS.<ref name="AppleKernelProgrammingGuide"/>

{{Quote|OS X is based on the Mach 3.0 microkernel, designed by [[Carnegie Mellon University]], and later adapted to the Power Macintosh by Apple and the Open Software Foundation Research Institute (now part of Silicomp). This was known as <code>osfmk</code>, and was part of MkLinux (http://www.mklinux.org). Later, this and code from OSF’s commercial development efforts were incorporated into Darwin’s kernel. Throughout this evolutionary process, the Mach APIs used in OS X diverged in many ways from the original CMU Mach 3 APIs.

You may find older versions of the Mach source code interesting, both to satisfy historical curiosity and to avoid remaking mistakes made in earlier implementations.|Apple, Inc.|Kernel Programming Guide: Mach API Reference<ref name="AppleKernelProgrammingGuide"/>}}

==Releases==
{| class="wikitable" border="1"
|-
!Version
!Approx. date
!Notes
|-
|DR1
|May 1996
|Linux 1.3
|-
|DR2
|September 1996
|Many bug fixes
|-
|DR2.1
|May 1997
|Linux 2.0; support for PCI machines
|-
|DR3
|July 1998
|
|-
|R1
|December 1999
|
|-
|pre-R2
|August 2002
|
|}

==See also==
{{Portal bar|Linux|Free and open-source software}}
* [[L4Linux]]
* [[Darwin (operating system)]]
* [[PureDarwin]]
* [[Copland (operating system)]]
* [[Taligent]]
* [[Workplace OS]]

==References==
{{reflist |refs=
<ref name="HistoryofLinuxforthePPC">{{cite web |title=History of Linux for the PowerPC |last=Hatle |first=Mark |date=February 1999 |url=http://gate.crashing.org/doc/ppc/doc003.htm |url-status=dead |archive-url=https://web.archive.org/web/20130313210840/http://gate.crashing.org/doc/ppc/doc003.htm |archive-date=March 13, 2013 |access-date=April 4, 2013}}</ref>
<ref name="MkLinuxApple">{{cite web |url=http://www.mklinux.apple.com/ |title=What is MkLinux? |publisher=Apple Computer, Inc. |url-status=dead |archive-url=https://web.archive.org/web/19990423202143/http://www.mklinux.apple.com/ |archive-date=April 23, 1999 |access-date=May 25, 2013}}</ref>
<ref name="LinuxonOSFMach3">{{cite web |title=Linux on the OSF Mach3 microkernel |url=http://bat8.inria.fr/~lang/hotlist/free/licence/fsf96/mklinux.html |url-status=dead |archive-url=https://web.archive.org/web/20120211081545/http://bat8.inria.fr/~lang/hotlist/free/licence/fsf96/mklinux.html |archive-date=February 11, 2012 |access-date=April 4, 2013 |last1=Barbou des Places |first1=François |last2=Stephen |first2=Nick |last3=Reynolds |first3=Franklin D. |date=January 12, 1996 |publisher=OSF Research Institute |location=Grenoble and Cambridge}}</ref>
<ref name="MkLinuxbookEnglish">{{cite book |last=Morin |first=Rich |others=Apple Computer, Inc. |title=MkLinux: microkernel Linux for the Power Macintosh |publisher=Prime Time Freeware |orig-year=First published March 1997 |date=1998 |edition=3 |isbn=978-1-881957-24-9 |url=https://archive.org/details/mklinux00rich |oclc=717806070 |location=Sunnyvale, CA |type=Book and 2 CD-ROMs |language=en |access-date=May 25, 2013 |url-access=registration}}</ref>
<ref name="MkLinuxbookJapanese">{{cite book |last=Morin |first=Rich |others=Apple Computer, Inc.; translation by Kosumo Puranetto |title=MkLinux: Microkernel Linux for the Power Macintosh |publisher=Asuki |orig-year=First published March 1997 |date=May 2000 |series=Ascii Books |isbn=9784756134219 |oclc=122901286 |location=Tokyo |type=Book and 2 CD-ROMs |language=ja}}</ref>
<ref name="AppleKernelProgrammingGuide">{{cite web |title=Kernel Programming Guide: Mach API Reference |url=https://developer.apple.com/library/content/documentation/Darwin/Conceptual/KernelProgramming/About/About.html |publisher=Apple, Inc |access-date=August 24, 2017}}</ref>
<ref name="Linux Gains">{{cite magazine |last=Stauffer |first=Todd |title=Linux Gains Ground on Macs |url=http://www.mactech.com/articles/mactech/Vol.15/15.07/LinuxGainsGround/ |magazine=MacTech |date=1999 |volume=5 |issue=7 |publisher=Xplain Corporation |access-date=October 3, 2017}}</ref>
}}

==External links==
*{{Official website}}

{{Apple operating systems}}
{{Linux kernel}}
{{Microkernel}}
{{Mach-like}}
{{Operating system}}

[[Category:Apple Inc. operating systems]]
[[Category:Discontinued Linux distributions]]
[[Category:PowerPC operating systems]]
[[Category:Microkernel-based operating systems]]
[[Category:Mach (kernel)]]
[[Category:Linux kernel variant]]
[[Category:Microkernels]]
[[Category:1996 software]]
[[Category:Linux distributions]]
[[Category:Unix variants]]