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vevent"><caption class="infobox-title summary">Vanguard</caption><tbody><tr><th scope="row" class="infobox-label" style="white-space: nowrap;"><a href="/wiki/Programmer" title="Programmer">Developer</a></th><td class="infobox-data">Ross Finlayson, <a href="/wiki/Apple_Computer" class="mw-redirect" title="Apple Computer">Apple Computer</a></td></tr><tr><th scope="row" class="infobox-label" style="white-space: nowrap;">OS family</th><td class="infobox-data"><a href="/wiki/V_(operating_system)" title="V (operating system)">V-System</a></td></tr><tr><th scope="row" class="infobox-label" style="white-space: nowrap;">Working state</th><td class="infobox-data">Discontinued</td></tr><tr><th scope="row" class="infobox-label" style="white-space: nowrap;">Source model</th><td class="infobox-data">Closed-source</td></tr><tr><th scope="row" class="infobox-label" style="white-space: nowrap;">Initial release</th><td class="infobox-data">1993<span class="noprint">; 32 years ago</span><span style="display:none"> (<span class="bday dtstart published updated">1993</span>)</span></td></tr><tr><th scope="row" class="infobox-label" style="white-space: nowrap;">Marketing target</th><td class="infobox-data"><a href="/wiki/Desktop_computer" title="Desktop computer">Desktop computers</a></td></tr><tr><th scope="row" class="infobox-label" style="white-space: nowrap;"><a href="/wiki/Natural_language" title="Natural language">Available in</a></th><td class="infobox-data">English</td></tr><tr><th scope="row" class="infobox-label" style="white-space: nowrap;">Platforms</th><td class="infobox-data"><a href="/wiki/Motorola_68000_series" title="Motorola 68000 series">Motorola 68000 series</a></td></tr><tr><th scope="row" class="infobox-label" style="white-space: nowrap;"><a href="/wiki/Kernel_(operating_system)" title="Kernel (operating system)">Kernel</a> type</th><td class="infobox-data"><a href="/wiki/Microkernel" title="Microkernel">Microkernel</a></td></tr><tr><th scope="row" class="infobox-label" style="white-space: nowrap;">Preceded by</th><td class="infobox-data"><a href="/wiki/V_(operating_system)" title="V (operating system)">V-System</a></td></tr></tbody></table> <p><b>Vanguard</b> is a discontinued experimental <a href="/wiki/Microkernel" title="Microkernel">microkernel</a> developed at <a href="/wiki/Apple_Computer" class="mw-redirect" title="Apple Computer">Apple Computer</a>,<sup id="cite_ref-USENIX_1-0" class="reference"><a href="#cite_note-USENIX-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup> in the research-oriented <a href="/wiki/Apple_Advanced_Technology_Group" title="Apple Advanced Technology Group">Apple Advanced Technology Group</a> (ATG) in the early 1990s. Based on the <a href="/wiki/V_(operating_system)" title="V (operating system)">V-System</a>, Vanguard introduced standardized <a href="/wiki/Object_(computer_science)" title="Object (computer science)">object</a> identifiers and a unique <i>message chaining</i> system for improved performance. Vanguard was not used in any of Apple's commercial products. Development ended in 1993 when Ross Finlayson, the project's main investigator, left Apple. </p> <meta property="mw:PageProp/toc" /> <div class="mw-heading mw-heading2"><h2 id="Basic_concepts">Basic concepts</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Vanguard_(microkernel)&action=edit&section=1" title="Edit section: Basic concepts"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Vanguard was generally very similar to the V-System, but added support for true <a href="/wiki/Object-oriented_programming" title="Object-oriented programming">object-oriented programming</a> of the <a href="/wiki/Operating_system" title="Operating system">operating system</a>. This meant that <a href="/wiki/Kernel_(operating_system)" title="Kernel (operating system)">kernel</a> and <a href="/wiki/Server_(computing)" title="Server (computing)">server</a> interfaces were exported as objects, which could be <i><a href="/wiki/Inheritance_(object-oriented_programming)" title="Inheritance (object-oriented programming)">inherited</a></i> and extended in new code. This change has no visible effect on the system, it is mainly a change in the <a href="/wiki/Source_code" title="Source code">source code</a> that makes programming easier. </p><p>For example, Vanguard had an <a href="/wiki/Input/output" title="Input/output">input/output</a> (I/O) <a href="/wiki/Class_(computer_programming)" title="Class (computer programming)">class</a> which was supported by several different servers, for example, networking and <a href="/wiki/File_server" title="File server">file servers</a>, which new applications could interact with by importing the I/O <a href="/wiki/Interface_(computing)" title="Interface (computing)">interface</a> and calling methods. This also made writing new servers much easier, because they had a standard to program to, and were able to share code more easily. </p> <div class="mw-heading mw-heading2"><h2 id="V_messaging_semantics">V messaging semantics</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Vanguard_(microkernel)&action=edit&section=2" title="Edit section: V messaging semantics"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>A key concept to almost all microkernels is to break down one larger kernel into a set of communicating <i>servers</i>. Instead of having one larger program controlling all of the hardware of a computer system, the various duties are apportioned among smaller programs that are given rights to control different parts of the machine. For example, one server can be given control of the networking hardware, while another has the task of managing the <a href="/wiki/Hard_disk_drive" title="Hard disk drive">hard disk drives</a>. Another server would handle the <a href="/wiki/File_system" title="File system">file system</a>, calling both of these lower-level servers. User applications ask for services by sending <i>messages</i> to these servers, using some form of <a href="/wiki/Inter-process_communication" title="Inter-process communication">inter-process communications</a> (IPC), in contrast to asking the kernel to do this work via a <i><a href="/wiki/System_call" title="System call">system call</a></i> (syscall) or <i><a href="/wiki/Trap_(computing)" class="mw-redirect" title="Trap (computing)">trap</a></i>. </p><p>Under V the IPC system appears to be conceptually modeled on <a href="/wiki/Remote_procedure_call" title="Remote procedure call">remote procedure calls</a> (RPC) from the <a href="/wiki/Client_(computing)" title="Client (computing)">client</a> application's perspective. The client imported an <i>interface definition file</i> containing information about the calls supported by the kernel, or other applications, and then used this definition to package up requests. When called, the kernel would immediately take over, examine the results, and pass the information off to the right handler, potentially within the kernel. Any results were then handed back through the kernel to the client. </p><p>The operation of the system as it appears to the client application is very similar to working with a normal <a href="/wiki/Monolithic_kernel" title="Monolithic kernel">monolithic kernel</a>. Although the results passed back might come from a third party handler, this was essentially invisible to the client. Servers handling these requests operated in a similar fashion to the clients, opening connections with the kernel to pass data. However, servers generally spawned new threads as required to handle longer-lasting requests. When these were handled and the responses posted, the thread could be de-allocated and the servers could go into a <i>receive mode</i> awaiting further requests. </p><p>In contrast, most microkernel systems are based on a model of <a href="/wiki/Asynchronous_communication" title="Asynchronous communication">asynchronous communications</a>, instead of synchronous <a href="/wiki/Subroutine" class="mw-redirect" title="Subroutine">procedure</a> calls. The canonical microkernel system, <a href="/wiki/Mach_(kernel)" title="Mach (kernel)">Mach</a>, modeled messages as I/O, which has several important side-effects. Primary among these is that the normal task <a href="/wiki/Scheduling_(computing)" title="Scheduling (computing)">schedulers</a> under <a href="/wiki/Unix-like" title="Unix-like">Unix-like</a> systems will normally block a client that is waiting on an I/O request, so in this way the actions of pausing and restarting applications waiting on messages was already built into the underlying system. The downside to this approach is that the scheduler is fairly <i>heavyweight</i>, and calling it was a serious performance bottleneck and led to extensive development efforts to improve its performance. Under the V-System model, the <a href="/wiki/Message_passing" title="Message passing">message passing</a> overhead is reduced because the process scheduler does not need to be consulted, there is no question as to what should next be run, which is the server being called. The downside to the V approach is that it requires more work for the server if the response may take some time to process. </p> <div class="mw-heading mw-heading2"><h2 id="Chaining">Chaining</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Vanguard_(microkernel)&action=edit&section=3" title="Edit section: Chaining"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>One major addition to the IPC system under Vanguard, in contrast to V, was the concept of <i>message chains</i>, allowing one message to be sent between several interacting servers in one round-trip. In theory, chaining could improve the performance of common multi-step operations. </p><p>Consider the case where a client application must read a file. Normally this would require one message to the kernel to find the file server, then three more messages to the file server: one to resolve the file name into an object id, another to open that id, then finally another to read the file. Using Vanguard's chaining, one message could be constructed by the client that contained all of these requests. The message would be sent to the kernel, and then passed off to the file server which would handle all three requests before finally returning data. </p><p>Much of the performance problem normally associated with microkernel systems are due to the <a href="/wiki/Context_switch" title="Context switch">context switches</a> as messages are passed back and forth between applications. In the example above running on a V system, there would have to be a total of eight context switches; two for each request as the client switched to and from the kernel. In Vanguard using a chain would reduce this to only three switches; one out of the client into the kernel, another from the kernel to the file server, and finally from the server back to the client. In some cases the overhead of a context switch is greater than the time it takes to actually run the request, so Vanguard's chaining mechanism could result in real-world performance improvements. </p> <div class="mw-heading mw-heading2"><h2 id="Object_naming">Object naming</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Vanguard_(microkernel)&action=edit&section=4" title="Edit section: Object naming"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>V had also introduced a simple distributed <i><a href="/wiki/Directory_service" title="Directory service">name service</a></i>. The service stored <i>well known</i> character names representing various objects in a distributed V system, for example, <code>2nd floor laser printer</code>. Applications could ask the <i><a href="/wiki/Name_server" title="Name server">name server</a></i> for objects by name, and would be handed back an identifier that would allow them to interact with that object. The name service was not a separate server, and was managed by code in the kernel. Contrast this with the full <i>name server</i> under the operating system <a href="/wiki/Spring_(operating_system)" title="Spring (operating system)">Spring</a>, which not only knew about objects inside the system, but was also used by other servers on the system to translate their private names, for example, file names and IP addresses. </p><p>Under the V-System, objects in servers were referred to via an <i>ad hoc</i> <a href="/wiki/Public-key_cryptography" title="Public-key cryptography">private key</a> of some sort, say a <a href="/wiki/32-bit_computing" title="32-bit computing">32-bit</a> integer. Clients would pass these keys into the servers to maintain a conversation about a specific task. For example, an application might ask the kernel for the <i>file system</i> and be handed a 32-bit key representing a program id, and then use that key to send a message to the file system asking it to open the file <code>my addresses</code>, which would result in a <a href="/wiki/64-bit_computing" title="64-bit computing">64-bit</a> key being handed back. The keys in this example are proprietary to the servers, there was no common key format being used across the system. </p><p>This sort of name resolving was so common under V that the authors decided to make these keys first-class citizens under Vanguard. Instead of using whatever object ID's the servers just happened to use, under Vanguard all servers were expected to understand and return a globally unique <a href="/wiki/128-bit_computing" title="128-bit computing">128-bit</a> key, the first 64-bits containing a server identifier, the second identifying an object in that server. The server id was maintained in the kernel, allowing it to hand off the message over the network if the server being referenced was on a remote machine. To the client this was invisible. It is unclear if the id's were assigned randomly to preclude successful <i>guessing</i> by ill-intentioned software. </p> <div class="mw-heading mw-heading2"><h2 id="References">References</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Vanguard_(microkernel)&action=edit&section=5" title="Edit section: References"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <style data-mw-deduplicate="TemplateStyles:r1239543626">.mw-parser-output .reflist{margin-bottom:0.5em;list-style-type:decimal}@media screen{.mw-parser-output .reflist{font-size:90%}}.mw-parser-output .reflist .references{font-size:100%;margin-bottom:0;list-style-type:inherit}.mw-parser-output .reflist-columns-2{column-width:30em}.mw-parser-output .reflist-columns-3{column-width:25em}.mw-parser-output .reflist-columns{margin-top:0.3em}.mw-parser-output .reflist-columns ol{margin-top:0}.mw-parser-output .reflist-columns li{page-break-inside:avoid;break-inside:avoid-column}.mw-parser-output .reflist-upper-alpha{list-style-type:upper-alpha}.mw-parser-output .reflist-upper-roman{list-style-type:upper-roman}.mw-parser-output .reflist-lower-alpha{list-style-type:lower-alpha}.mw-parser-output .reflist-lower-greek{list-style-type:lower-greek}.mw-parser-output .reflist-lower-roman{list-style-type:lower-roman}</style><div class="reflist"> <div class="mw-references-wrap"><ol class="references"> <li id="cite_note-USENIX-1"><span class="mw-cite-backlink"><b><a href="#cite_ref-USENIX_1-0">^</a></b></span> <span class="reference-text"><style data-mw-deduplicate="TemplateStyles:r1238218222">.mw-parser-output cite.citation{font-style:inherit;word-wrap:break-word}.mw-parser-output .citation q{quotes:"\"""\"""'""'"}.mw-parser-output .citation:target{background-color:rgba(0,127,255,0.133)}.mw-parser-output .id-lock-free.id-lock-free a{background:url("//upload.wikimedia.org/wikipedia/commons/6/65/Lock-green.svg")right 0.1em center/9px no-repeat}.mw-parser-output .id-lock-limited.id-lock-limited a,.mw-parser-output .id-lock-registration.id-lock-registration a{background:url("//upload.wikimedia.org/wikipedia/commons/d/d6/Lock-gray-alt-2.svg")right 0.1em center/9px no-repeat}.mw-parser-output .id-lock-subscription.id-lock-subscription a{background:url("//upload.wikimedia.org/wikipedia/commons/a/aa/Lock-red-alt-2.svg")right 0.1em center/9px no-repeat}.mw-parser-output .cs1-ws-icon a{background:url("//upload.wikimedia.org/wikipedia/commons/4/4c/Wikisource-logo.svg")right 0.1em center/12px no-repeat}body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-free a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-limited a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-registration a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-subscription a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .cs1-ws-icon a{background-size:contain;padding:0 1em 0 0}.mw-parser-output .cs1-code{color:inherit;background:inherit;border:none;padding:inherit}.mw-parser-output .cs1-hidden-error{display:none;color:var(--color-error,#d33)}.mw-parser-output .cs1-visible-error{color:var(--color-error,#d33)}.mw-parser-output .cs1-maint{display:none;color:#085;margin-left:0.3em}.mw-parser-output .cs1-kern-left{padding-left:0.2em}.mw-parser-output .cs1-kern-right{padding-right:0.2em}.mw-parser-output .citation .mw-selflink{font-weight:inherit}@media screen{.mw-parser-output .cs1-format{font-size:95%}html.skin-theme-clientpref-night .mw-parser-output .cs1-maint{color:#18911f}}@media screen and (prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .cs1-maint{color:#18911f}}</style><cite id="CITEREFFinlaysonHenneckeGoldberg1993" class="citation conference cs1">Finlayson, Ross S.; Hennecke, Mark D.; Goldberg, Steven L. (20–23 September 1993). <a rel="nofollow" class="external text" href="https://www.usenix.org/legacy/publications/library/proceedings/micro93/full_papers/finlayson.txt"><i>From V to Vanguard: The Evolution of a Distributed, Object-Oriented Microkernel Interface</i></a>. Proceedings of the USENIX Microkernels and Other Kernel Architectures Symposium. <i>USENIX</i>. San Diego, California.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=conference&rft.jtitle=USENIX&rft.atitle=From+V+to+Vanguard%3A+The+Evolution+of+a+Distributed%2C+Object-Oriented+Microkernel+Interface&rft.date=1993-09-20%2F1993-09-23&rft.aulast=Finlayson&rft.aufirst=Ross+S.&rft.au=Hennecke%2C+Mark+D.&rft.au=Goldberg%2C+Steven+L.&rft_id=https%3A%2F%2Fwww.usenix.org%2Flegacy%2Fpublications%2Flibrary%2Fproceedings%2Fmicro93%2Ffull_papers%2Ffinlayson.txt&rfr_id=info%3Asid%2Fen.wikipedia.org%3AVanguard+%28microkernel%29" class="Z3988"></span></span> </li> </ol></div></div> <div class="navbox-styles"><style data-mw-deduplicate="TemplateStyles:r1129693374">.mw-parser-output .hlist dl,.mw-parser-output .hlist ol,.mw-parser-output .hlist ul{margin:0;padding:0}.mw-parser-output .hlist dd,.mw-parser-output .hlist dt,.mw-parser-output .hlist li{margin:0;display:inline}.mw-parser-output .hlist.inline,.mw-parser-output .hlist.inline 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href="/wiki/Template:Apple_operating_systems" title="Template:Apple operating systems"><abbr title="View this template">v</abbr></a></li><li class="nv-talk"><a href="/wiki/Template_talk:Apple_operating_systems" title="Template talk:Apple operating systems"><abbr title="Discuss this template">t</abbr></a></li><li class="nv-edit"><a href="/wiki/Special:EditPage/Template:Apple_operating_systems" title="Special:EditPage/Template:Apple operating systems"><abbr title="Edit this template">e</abbr></a></li></ul></div><div id="Operating_systems_by_Apple405" style="font-size:114%;margin:0 4em">Operating systems by <a href="/wiki/Apple_Inc." title="Apple Inc.">Apple</a></div></th></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Apple_II" title="Apple II">Apple II</a>, <a href="/wiki/Apple_III" title="Apple III">III</a>, <a href="/wiki/Apple_Lisa" title="Apple Lisa">Lisa</a></th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Apple_II" title="Apple II">Apple II</a> <ul><li><a href="/wiki/Apple_DOS" title="Apple DOS">Apple DOS</a></li> <li><a href="/wiki/Apple_ProDOS" title="Apple ProDOS">ProDOS</a></li> <li><a href="/wiki/Apple_GS/OS" title="Apple GS/OS">GS/OS</a></li></ul></li> <li><a href="/wiki/Apple_III" title="Apple III">Apple III</a> <ul><li><a href="/wiki/Apple_SOS" title="Apple SOS">SOS</a></li></ul></li> <li><a href="/wiki/Apple_Lisa" title="Apple Lisa">Lisa</a> <ul><li><a href="/wiki/Apple_Lisa#Software" title="Apple Lisa">Lisa OS</a></li> <li><a href="/wiki/MacWorks_XL" title="MacWorks XL">MacWorks</a></li></ul></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Mac_operating_systems" title="Mac operating systems">Mac</a></th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"></div><table class="nowraplinks navbox-subgroup" style="border-spacing:0"><tbody><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Classic_Mac_OS" title="Classic Mac OS">Classic Mac OS</a></th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/System_1" title="System 1">System 1</a></li> <li><a href="/wiki/Classic_Mac_OS#System_1,_2,_3,_and_4" title="Classic Mac OS">Systems 2, 3, and 4</a></li> <li><a href="/wiki/Classic_Mac_OS#System_Software_5" title="Classic Mac OS">System 5</a></li> <li><a href="/wiki/System_6" title="System 6">System 6</a></li> <li><a href="/wiki/System_7" title="System 7">System 7</a></li> <li><a href="/wiki/Mac_OS_8" title="Mac OS 8">Mac OS 8</a></li> <li><a href="/wiki/Mac_OS_9" title="Mac OS 9">Mac OS 9</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/MacOS" title="MacOS">macOS</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/MacOS_version_history" title="MacOS version history">History</a> <ul><li><a href="/wiki/NeXTSTEP" title="NeXTSTEP">NeXTSTEP</a></li> <li><a href="/wiki/OpenStep" title="OpenStep">OpenStep</a></li> <li><a href="/wiki/Rhapsody_(operating_system)" title="Rhapsody (operating system)">Rhapsody</a></li> <li><a href="/wiki/Mac_OS_X_Public_Beta" title="Mac OS X Public Beta">Public Beta</a></li></ul></li> <li>Core <ul><li><a href="/wiki/Darwin_(operating_system)" title="Darwin (operating system)">Darwin</a> <ul><li><a href="/wiki/XNU" title="XNU">XNU</a></li></ul></li></ul></li> <li>Desktop <ul><li>Mac OS X <ul><li><a href="/wiki/Mac_OS_X_Public_Beta" title="Mac OS X Public Beta">Public Beta</a></li> <li><a href="/wiki/Mac_OS_X_10.0" title="Mac OS X 10.0">10.0 (Cheetah)</a></li> <li><a href="/wiki/Mac_OS_X_10.1" title="Mac OS X 10.1">10.1 (Puma)</a></li> <li><a href="/wiki/Mac_OS_X_Jaguar" title="Mac OS X Jaguar">10.2 Jaguar</a></li> <li><a href="/wiki/Mac_OS_X_Panther" title="Mac OS X Panther">10.3 Panther</a></li> <li><a href="/wiki/Mac_OS_X_Tiger" title="Mac OS X Tiger">10.4 Tiger</a></li> <li><a href="/wiki/Mac_OS_X_Leopard" title="Mac OS X Leopard">10.5 Leopard</a></li> <li><a href="/wiki/Mac_OS_X_Snow_Leopard" title="Mac OS X Snow Leopard">10.6 Snow Leopard</a></li> <li><a href="/wiki/Mac_OS_X_Lion" class="mw-redirect" title="Mac OS X Lion">10.7 Lion</a></li></ul></li> <li>OS X <ul><li><a href="/wiki/OS_X_Mountain_Lion" title="OS X Mountain Lion">10.8 Mountain Lion</a></li> <li><a href="/wiki/OS_X_Mavericks" title="OS X Mavericks">10.9 Mavericks</a></li> <li><a href="/wiki/OS_X_Yosemite" title="OS X Yosemite">10.10 Yosemite</a></li> <li><a href="/wiki/OS_X_El_Capitan" title="OS X El Capitan">10.11 El Capitan</a></li></ul></li> <li>macOS <ul><li><a href="/wiki/MacOS_Sierra" title="MacOS Sierra">10.12 Sierra</a></li> <li><a href="/wiki/MacOS_High_Sierra" title="MacOS High Sierra">10.13 High Sierra</a></li> <li><a href="/wiki/MacOS_Mojave" title="MacOS Mojave">10.14 Mojave</a></li> <li><a href="/wiki/MacOS_Catalina" title="MacOS Catalina">10.15 Catalina</a></li> <li><a href="/wiki/MacOS_Big_Sur" title="MacOS Big Sur">11 Big Sur</a></li> <li><a href="/wiki/MacOS_Monterey" title="MacOS Monterey">12 Monterey</a></li> <li><a href="/wiki/MacOS_Ventura" title="MacOS Ventura">13 Ventura</a></li> <li><a href="/wiki/MacOS_Sonoma" title="MacOS Sonoma">14 Sonoma</a></li> <li><a href="/wiki/MacOS_Sequoia" title="MacOS Sequoia">15 Sequoia</a></li></ul></li></ul></li> <li><a href="/wiki/MacOS_Server" class="mw-redirect" title="MacOS Server">Server</a> <ul><li><a href="/wiki/Mac_OS_X_Server_1.0" title="Mac OS X Server 1.0">Mac OS X Server 1.0</a></li></ul></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Other projects</th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li>Shipped <ul><li><a href="/wiki/A/ROSE" title="A/ROSE">A/ROSE</a></li> <li><a href="/wiki/A/UX" title="A/UX">A/UX</a></li> <li><a href="/wiki/AIX_for_Apple_Network_Servers" class="mw-redirect" title="AIX for Apple Network Servers">AIX for Apple Network Servers</a></li> <li><a href="/wiki/Macintosh_Application_Environment" title="Macintosh Application Environment">MAE</a></li> <li><a href="/wiki/MkLinux" title="MkLinux">MkLinux</a></li> <li><a href="/wiki/PowerOpen_Environment" title="PowerOpen Environment">PowerOpen Environment</a></li></ul></li> <li>Cancelled <ul><li><a href="/wiki/Star_Trek_project" title="Star Trek project">Star Trek</a></li> <li><a href="/wiki/Taligent" title="Taligent">Taligent</a></li> <li><a href="/wiki/Copland_(operating_system)" title="Copland (operating system)">Copland</a> <ul><li><a href="/wiki/Nukernel" title="Nukernel">Nukernel</a></li></ul></li> <li><a class="mw-selflink selflink">Vanguard</a></li></ul></li></ul> </div></td></tr></tbody></table><div></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/IOS" title="IOS">iOS</a> derivatives</th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"></div><table class="nowraplinks navbox-subgroup" style="border-spacing:0"><tbody><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/IOS" title="IOS">iOS</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li>iPhone OS <ul><li><a href="/wiki/IPhone_OS_1" title="IPhone OS 1">1</a></li> <li><a href="/wiki/IPhone_OS_2" title="IPhone OS 2">2</a></li> <li><a href="/wiki/IPhone_OS_3" title="IPhone OS 3">3</a></li></ul></li> <li>iOS <ul><li><a href="/wiki/IOS_4" title="IOS 4">4</a></li> <li><a href="/wiki/IOS_5" title="IOS 5">5</a></li> <li><a href="/wiki/IOS_6" title="IOS 6">6</a></li> <li><a href="/wiki/IOS_7" title="IOS 7">7</a></li> <li><a href="/wiki/IOS_8" title="IOS 8">8</a></li> <li><a href="/wiki/IOS_9" title="IOS 9">9</a></li> <li><a href="/wiki/IOS_10" title="IOS 10">10</a></li> <li><a href="/wiki/IOS_11" title="IOS 11">11</a></li> <li><a href="/wiki/IOS_12" title="IOS 12">12</a></li> <li><a href="/wiki/IOS_13" title="IOS 13">13</a></li> <li><a href="/wiki/IOS_14" title="IOS 14">14</a></li> <li><a href="/wiki/IOS_15" title="IOS 15">15</a></li> <li><a href="/wiki/IOS_16" title="IOS 16">16</a></li> <li><a href="/wiki/IOS_17" title="IOS 17">17</a></li> <li><a href="/wiki/IOS_18" title="IOS 18">18</a></li></ul></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/IPadOS" title="IPadOS">iPadOS</a></th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/IPadOS_13" title="IPadOS 13">13</a></li> <li><a href="/wiki/IPadOS_14" title="IPadOS 14">14</a></li> <li><a href="/wiki/IPadOS_15" title="IPadOS 15">15</a></li> <li><a href="/wiki/IPadOS_16" title="IPadOS 16">16</a></li> <li><a href="/wiki/IPadOS_17" title="IPadOS 17">17</a></li> <li><a href="/wiki/IPadOS_18" title="IPadOS 18">18</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Others</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/TvOS" title="TvOS">tvOS</a> <ul><li><a href="/wiki/Apple_TV#Software" title="Apple TV">Apple TV Software</a></li></ul></li> <li><a href="/wiki/VisionOS" title="VisionOS">visionOS</a></li> <li><a href="/wiki/WatchOS" title="WatchOS">watchOS</a></li> <li><a href="/wiki/AudioOS" class="mw-redirect" title="AudioOS">audioOS</a></li> <li><a href="/wiki/BridgeOS" title="BridgeOS">bridgeOS</a></li></ul> </div></td></tr></tbody></table><div></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Others</th><td class="navbox-list-with-group navbox-list navbox-even hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Newton_OS" title="Newton OS">Newton OS</a></li> <li><a href="/wiki/History_of_iTunes#Devices" title="History of iTunes">iPod software</a></li></ul> </div></td></tr><tr><td class="navbox-abovebelow" colspan="2"><div><span class="noviewer" typeof="mw:File"><span title="List-Class article"><img alt="" src="//upload.wikimedia.org/wikipedia/en/thumb/d/db/Symbol_list_class.svg/16px-Symbol_list_class.svg.png" decoding="async" width="16" height="16" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/d/db/Symbol_list_class.svg/23px-Symbol_list_class.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/d/db/Symbol_list_class.svg/31px-Symbol_list_class.svg.png 2x" data-file-width="180" data-file-height="185" /></span></span> <a href="/wiki/List_of_Apple_operating_systems" title="List of Apple operating systems">List</a> • <span class="noviewer" typeof="mw:File"><span title="Category"><img alt="" src="//upload.wikimedia.org/wikipedia/en/thumb/9/96/Symbol_category_class.svg/16px-Symbol_category_class.svg.png" decoding="async" width="16" height="16" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/9/96/Symbol_category_class.svg/23px-Symbol_category_class.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/9/96/Symbol_category_class.svg/31px-Symbol_category_class.svg.png 2x" data-file-width="180" data-file-height="185" /></span></span> <a href="/wiki/Category:Apple_Inc._operating_systems" title="Category:Apple Inc. operating systems">Category</a></div></td></tr></tbody></table></div> <div class="navbox-styles"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1129693374" /><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1236075235" /></div><div role="navigation" class="navbox" aria-labelledby="Microkernels-nanokernels667" style="padding:3px"><table class="nowraplinks hlist mw-collapsible autocollapse navbox-inner" style="border-spacing:0;background:transparent;color:inherit"><tbody><tr><th scope="col" class="navbox-title" colspan="2"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1129693374" /><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1239400231" /><div class="navbar plainlinks hlist navbar-mini"><ul><li class="nv-view"><a href="/wiki/Template:Microkernel" title="Template:Microkernel"><abbr title="View this template">v</abbr></a></li><li class="nv-talk"><a href="/wiki/Template_talk:Microkernel" title="Template talk:Microkernel"><abbr title="Discuss this template">t</abbr></a></li><li class="nv-edit"><a href="/wiki/Special:EditPage/Template:Microkernel" title="Special:EditPage/Template:Microkernel"><abbr title="Edit this template">e</abbr></a></li></ul></div><div id="Microkernels-nanokernels667" style="font-size:114%;margin:0 4em"><a href="/wiki/Microkernel" title="Microkernel">Microkernels</a>-<a href="/wiki/Microkernel#Nanokernel" title="Microkernel">nanokernels</a></div></th></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Kernel_(operating_system)" title="Kernel (operating system)">Kernels</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"></div><table class="nowraplinks navbox-subgroup" style="border-spacing:0"><tbody><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/L4_microkernel_family" title="L4 microkernel family">L4</a> family</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><i><a href="/wiki/Eumel" title="Eumel">Eumel</a></i> → <i><a href="/wiki/L3_microkernel" class="mw-redirect" title="L3 microkernel">L3</a></i> → <a href="/wiki/L4_microkernel_family" title="L4 microkernel family">L4</a>°</li> <li><a href="/wiki/Open_Kernel_Labs" title="Open Kernel Labs">OKL4</a>°</li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Macintosh" class="mw-redirect" title="Macintosh">Macintosh</a> hosted</th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><i><a href="/wiki/Mac_OS_nanokernel" title="Mac OS nanokernel">Mac OS nanokernel</a></i></li> <li><i><a href="/wiki/NuKernel" class="mw-redirect" title="NuKernel">NuKernel</a></i></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Psion_(company)" title="Psion (company)">Psion</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><i><a href="/wiki/EKA1" title="EKA1">EKA1</a></i> → <i><a href="/wiki/EKA2" title="EKA2">EKA2</a></i>^°</li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Amiga" title="Amiga">Amiga</a>-type</th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><i><a href="/wiki/Exec_(Amiga)" title="Exec (Amiga)">Exec</a></i> <ul><li><a href="/wiki/Exec_(Amiga)#ExecSG" title="Exec (Amiga)">ExecSG</a></li></ul></li> <li><a href="/wiki/Quark_(kernel)" title="Quark (kernel)">Quark</a></li> <li><i><a href="/wiki/WarpOS" title="WarpOS">WarpOS</a></i></li></ul> </div></td></tr></tbody></table><div> <ul><li><i><a href="/wiki/Adaptive_Domain_Environment_for_Operating_Systems" title="Adaptive Domain Environment for Operating Systems">ADEOS</a></i>°</li> <li><i><a href="/wiki/EROS_(microkernel)" title="EROS (microkernel)">EROS</a></i>^°</li> <li><i><a href="/wiki/K42" title="K42">K42</a></i>°</li> <li>Little Kernel</li> <li><i><a href="/wiki/Mach_(kernel)" title="Mach (kernel)">Mach</a></i>° <ul><li><a href="/wiki/GNU_Mach" title="GNU Mach">GNU Mach</a>°</li></ul></li> <li><i><a href="/wiki/MicroEmpix" title="MicroEmpix">MicroEmpix</a></i></li> <li><a href="/wiki/Green_Hills_Software#Real-time_operating_systems" title="Green Hills Software">µ-velOSity</a>^</li> <li><i><a href="/wiki/Spring_(operating_system)#The_nucleus" title="Spring (operating system)">nucleus</a></i></li> <li>Off++ → Plan B</li> <li><i><a href="/wiki/Taligent#Pink_system" title="Taligent">Opus</a></i></li> <li><i><a href="/wiki/PowerUP_(accelerator)#PowerUP_software" title="PowerUP (accelerator)">PowerUP</a></i></li> <li><a href="/wiki/RTLinux" title="RTLinux">RTLinux</a>°</li> <li><a href="/wiki/TI-RTOS#RTOS_kernel_overview" title="TI-RTOS">TI-RTOS kernel</a>^°</li> <li><i><a class="mw-selflink selflink">Vanguard</a></i></li></ul></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Operating_system" title="Operating system">Operating<br />systems</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"></div><table class="nowraplinks navbox-subgroup" style="border-spacing:0"><tbody><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/POSIX" title="POSIX">POSIX</a> support</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"></div><table class="nowraplinks navbox-subgroup" style="border-spacing:0"><tbody><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Unix-like" title="Unix-like">Unix-like</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <li><i><a href="/wiki/ARX_(operating_system)" title="ARX (operating system)">ARX</a></i></li> <li><a href="/wiki/GNU_Hurd" title="GNU Hurd">GNU Hurd</a>°</li> <li><i><a href="/wiki/Lites" title="Lites">Lites</a></i></li> <li><i><a href="/wiki/Meiko_Scientific#MeikOS" title="Meiko Scientific">MeikOS</a></i></li> <li><a href="/wiki/Minix" title="Minix">Minix</a>° <ul><li><a href="/wiki/Minix-vmd" class="mw-redirect" title="Minix-vmd">Minix-vmd</a>°</li> <li><a href="/wiki/Minix_3" title="Minix 3">Minix 3</a>°</li></ul></li> <li><i><a href="/wiki/MkLinux" title="MkLinux">MkLinux</a></i>°</li> <li><i><a href="/wiki/Multi-Environment_Real-Time" title="Multi-Environment Real-Time">Multi-Environment Real-Time</a></i>^ (<i>MERT</i> – <i>Unix-RT</i>)</li> <li><i><a href="/wiki/OS2000" title="OS2000">OS2000</a></i></li> <li><a href="/wiki/QNX" title="QNX">QNX</a>^</li> <li><a href="/wiki/Redox_(operating_system)" title="Redox (operating system)">Redox</a>°</li> <li><i><a href="/wiki/Spring_(operating_system)" title="Spring (operating system)">Spring</a></i></li> <li><a href="/wiki/Tinix" title="Tinix">Tinix</a></li> <li><i><a href="/wiki/UNICOS" title="UNICOS">UNICOS</a></i></li> <li><i><a href="/wiki/VSTa" title="VSTa">VSTa</a></i></li> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Partial</th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><i><a href="/wiki/ChorusOS" title="ChorusOS">ChorusOS</a>^</i></li> <li><a href="/wiki/Integrity_(operating_system)" title="Integrity (operating system)">Integrity</a>^</li> <li><a href="/wiki/Nucleus_RTOS" title="Nucleus RTOS">Nucleus RTOS</a>^</li> <li><a href="/wiki/NuttX" title="NuttX">NuttX</a>^°</li> <li><a href="/wiki/Operating_System_Embedded" class="mw-redirect" title="Operating System Embedded">OSE</a>^</li> <li><a href="/wiki/RIOT_(operating_system)" title="RIOT (operating system)">RIOT</a>^°</li></ul> </div></td></tr></tbody></table><div></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Capability-based_security" title="Capability-based security">Capability-based</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><i><a href="/wiki/GNOSIS" title="GNOSIS">GNOSIS</a></i> → <i><a href="/wiki/KeyKOS" title="KeyKOS">KeyKOS</a></i> → <i><a href="/wiki/EROS_(microkernel)" title="EROS (microkernel)">EROS</a></i> → CapROS</li> <li><i><a href="/wiki/Hydra_(operating_system)" title="Hydra (operating system)">Hydra</a></i></li> <li><a href="/wiki/L4_microkernel_family#High_assurance:_seL4" title="L4 microkernel family">seL4</a>^°</li> <li><i><a href="/wiki/Midori_(operating_system)" title="Midori (operating system)">Midori</a></i></li> <li><i><a href="/wiki/NLTSS" title="NLTSS">NLTSS</a></i></li> <li><i><a href="/wiki/HarmonyOS_NEXT" title="HarmonyOS NEXT">HarmonyOS NEXT</a> (<a href="/wiki/OpenHarmony" title="OpenHarmony">OpenHarmony</a>, <a href="/wiki/OpenHarmony#Oniro_OS" title="OpenHarmony">Oniro OS</a>)</i> → <i><a href="/wiki/HarmonyOS" title="HarmonyOS">HarmonyOS</a></i></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/L4_microkernel_family" title="L4 microkernel family">L4</a> kernel</th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/L4Linux" title="L4Linux">L<sup>4</sup>Linux</a>^°</li> <li><a href="/wiki/PikeOS" title="PikeOS">PikeOS</a>^</li> <li><i><a href="/wiki/REX_OS" title="REX OS">REX OS</a></i>^</li> <li><a href="/wiki/Wombat_(operating_system)" title="Wombat (operating system)">Wombat</a>^°</li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Java_virtual_machine" title="Java virtual machine">Java virtual machine</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><i><a href="/wiki/JavaOS" title="JavaOS">JavaOS</a></i> (<i><a href="/wiki/JavaOS#Chorus/Jazz" title="JavaOS">Chorus/Jazz</a></i>^ integrates <i><a href="/wiki/ChorusOS" title="ChorusOS">ChorusOS</a></i>^)</li> <li><i><a href="/wiki/JX_(operating_system)" title="JX (operating system)">JX</a></i>°</li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Macintosh" class="mw-redirect" title="Macintosh">Macintosh</a> hosted</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"></div><table class="nowraplinks navbox-subgroup" style="border-spacing:0"><tbody><tr><th id="Unix-like13" scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Unix-like" title="Unix-like">Unix-like</a></th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><i><a href="/wiki/MachTen" title="MachTen">MachTen</a></i></li> <li><i><a href="/wiki/MacMach" title="MacMach">MacMach</a></i></li></ul> </div></td></tr></tbody></table><div> <ul><li><i><a href="/wiki/Copland_(operating_system)" title="Copland (operating system)">Copland</a></i></li> <li><i><a href="/wiki/Mac_OS_8#Mac_OS_8.6" title="Mac OS 8">Classic Mac OS</a></i> (<a href="/wiki/PowerPC" title="PowerPC">PowerPC</a> kernel)</li></ul></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Psion_(company)" title="Psion (company)">Psion</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <li><i><a href="/wiki/EPOC_(operating_system)" title="EPOC (operating system)">EPOC</a></i> → <i><a href="/wiki/Symbian" title="Symbian">Symbian</a> OS</i>^°</li> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Amiga" title="Amiga">Amiga</a>-type</th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/AmigaOS" title="AmigaOS">AmigaOS</a></li> <li><a href="/wiki/AROS_Research_Operating_System" title="AROS Research Operating System">AROS</a>° <ul><li><a href="/wiki/AROS_Research_Operating_System#AspireOS" title="AROS Research Operating System">AspireOS</a>°</li> <li><a href="/wiki/AROS_Research_Operating_System#Broadway" title="AROS Research Operating System">Broadway</a>°</li> <li><a href="/wiki/AROS_Research_Operating_System#Icaros_Desktop" title="AROS Research Operating System">Icaros Desktop</a>°</li></ul></li> <li><a href="/wiki/MorphOS" title="MorphOS">MorphOS</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Microsoft" title="Microsoft">Microsoft</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Singularity_(operating_system)" title="Singularity (operating system)">Singularity</a></li> <li><a href="/wiki/ThreadX" title="ThreadX">ThreadX</a>^</li> <li><i><a href="/wiki/Verve_(operating_system)" title="Verve (operating system)">Verve</a></i></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/AIM_alliance" title="AIM alliance">AIM alliance</a></th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><i>Pink</i> → <i><a href="/wiki/Taligent" title="Taligent">Taligent</a> OS</i> → <i><a href="/wiki/Workplace_OS" title="Workplace OS">Workplace OS</a></i></li></ul> </div></td></tr></tbody></table><div> <ul><li><i><a href="/wiki/Amoeba_(operating_system)" title="Amoeba (operating system)">Amoeba</a></i>°</li> <li><i><a href="/wiki/BeRTOS" title="BeRTOS">BeRTOS</a></i>^°</li> <li><a href="/wiki/ChibiOS/RT" title="ChibiOS/RT">ChibiOS/RT</a>^°</li> <li><a href="/wiki/FreeRTOS" title="FreeRTOS">FreeRTOS</a>^°</li> <li><a href="/wiki/HelenOS" title="HelenOS">HelenOS</a>°</li> <li><a href="/wiki/Micro-Controller_Operating_Systems" title="Micro-Controller Operating Systems">µC/OS</a>^°</li> <li><a href="/wiki/MQX" title="MQX">MQX</a>^</li> <li><a href="/wiki/OpenComRTOS" title="OpenComRTOS">OpenComRTOS</a>^</li> <li><a href="/wiki/Phantom_OS" title="Phantom OS">Phantom OS</a>^°</li> <li><i><a href="/wiki/RC_4000_multiprogramming_system" title="RC 4000 multiprogramming system">RC 4000</a></i></li> <li><a href="/wiki/SharpOS" title="SharpOS">SharpOS</a>°</li> <li><i><a href="/wiki/SPIN_(operating_system)" title="SPIN (operating system)">SPIN</a></i>°</li> <li><i><a href="/wiki/Thoth_(operating_system)" title="Thoth (operating system)">Thoth</a></i>^ → <i><a href="/wiki/Harmony_(operating_system)" title="Harmony (operating system)">Harmony</a></i>^ → <i><a href="/wiki/V_(operating_system)" title="V (operating system)">V</a></i></li> <li><a href="/wiki/Versatile_Real-Time_Executive" title="Versatile Real-Time Executive">VRTX</a>^</li> <li><a href="/wiki/Zephyr_(operating_system)" title="Zephyr (operating system)">Zephyr</a>^°</li></ul></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Software_framework" title="Software framework">Frameworks</a>, <a href="/wiki/Software_development_kit" title="Software development kit">kits</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <li><a href="/wiki/Cosmos_(operating_system)" title="Cosmos (operating system)">Cosmos</a>°</li> <li><a href="/wiki/Genode" title="Genode">Genode</a>°</li> <li><a href="/wiki/TI-RTOS" title="TI-RTOS">TI-RTOS</a>^°</li> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Programmer" title="Programmer">Developers</a></th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Gordon_Bell_(QNX)" title="Gordon Bell (QNX)">Gordon Bell</a></li> <li><a href="/wiki/Thomas_Bushnell" title="Thomas Bushnell">Thomas Bushnell</a></li> <li><a href="/wiki/David_Cheriton" title="David Cheriton">David Cheriton</a></li> <li><a href="/wiki/Dan_Dodge" title="Dan Dodge">Dan Dodge</a></li> <li><a href="/wiki/Per_Brinch_Hansen" title="Per Brinch Hansen">Per Brinch Hansen</a></li> <li><a href="/wiki/Gernot_Heiser" title="Gernot Heiser">Gernot Heiser</a></li> <li><a href="/wiki/Jochen_Liedtke" title="Jochen Liedtke">Jochen Liedtke</a></li> <li><a href="/wiki/James_G._Mitchell" title="James G. Mitchell">James G. Mitchell</a></li> <li><a href="/wiki/Ike_Nassi" title="Ike Nassi">Ike Nassi</a></li> <li><a href="/wiki/Richard_Rashid" title="Richard Rashid">Richard Rashid</a></li> <li><a href="/wiki/Andrew_S._Tanenbaum" title="Andrew S. Tanenbaum">Andrew S. Tanenbaum</a></li> <li><a href="/wiki/Avie_Tevanian" title="Avie Tevanian">Avie Tevanian</a></li> <li><a href="/wiki/William_Wulf" title="William Wulf">William Wulf</a></li></ul> </div></td></tr><tr><td class="navbox-abovebelow" colspan="2"><div> <ul><li><i>Italics</i> <b>= discontinued</b></li> <li><b>^ = <a href="/wiki/Real-time_operating_system" title="Real-time operating system">Real-time</a></b></li> <li><b>° = <a href="/wiki/Open-source_software" title="Open-source software">Open-source software</a></b><br /><span class="noviewer" typeof="mw:File"><span title="Category"><img alt="" src="//upload.wikimedia.org/wikipedia/en/thumb/9/96/Symbol_category_class.svg/16px-Symbol_category_class.svg.png" decoding="async" width="16" height="16" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/9/96/Symbol_category_class.svg/23px-Symbol_category_class.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/9/96/Symbol_category_class.svg/31px-Symbol_category_class.svg.png 2x" data-file-width="180" data-file-height="185" /></span></span> <b><a href="/wiki/Category:Microkernel-based_operating_systems" title="Category:Microkernel-based operating systems">Category: Microkernel-based operating systems</a></b> <span class="noviewer" typeof="mw:File"><span title="Category"><img alt="" src="//upload.wikimedia.org/wikipedia/en/thumb/9/96/Symbol_category_class.svg/16px-Symbol_category_class.svg.png" decoding="async" width="16" height="16" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/9/96/Symbol_category_class.svg/23px-Symbol_category_class.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/9/96/Symbol_category_class.svg/31px-Symbol_category_class.svg.png 2x" data-file-width="180" data-file-height="185" /></span></span> <b><a href="/wiki/Category:Microkernels" title="Category:Microkernels">Category: Microkernels</a></b></li></ul> </div></td></tr></tbody></table></div>    </div><noscript><img src="https://login.wikimedia.org/wiki/Special:CentralAutoLogin/start?useformat=desktop&type=1x1&usesul3=0" alt="" width="1" height="1" style="border: none; position: absolute;"></noscript> <div class="printfooter" data-nosnippet="">Retrieved from "<a dir="ltr" href="https://en.wikipedia.org/w/index.php?title=Vanguard_(microkernel)&oldid=1222656152">https://en.wikipedia.org/w/index.php?title=Vanguard_(microkernel)&oldid=1222656152</a>"</div></div> <div id="catlinks" class="catlinks" data-mw="interface"><div id="mw-normal-catlinks" class="mw-normal-catlinks"><a href="/wiki/Help:Category" title="Help:Category">Categories</a>: <ul><li><a href="/wiki/Category:Microkernels" title="Category:Microkernels">Microkernels</a></li><li><a href="/wiki/Category:Apple_Inc._operating_systems" title="Category:Apple Inc. operating systems">Apple Inc. operating systems</a></li></ul></div><div id="mw-hidden-catlinks" class="mw-hidden-catlinks mw-hidden-cats-hidden">Hidden categories: <ul><li><a href="/wiki/Category:Articles_with_short_description" title="Category:Articles with short description">Articles with short description</a></li><li><a href="/wiki/Category:Short_description_is_different_from_Wikidata" title="Category:Short description is different from Wikidata">Short description is different from Wikidata</a></li></ul></div></div> </div> </main> </div> <div class="mw-footer-container"> <footer id="footer" class="mw-footer" > <ul id="footer-info"> <li id="footer-info-lastmod"> This page was last edited on 7 May 2024, at 04:56<span class="anonymous-show"> (UTC)</span>.</li> <li id="footer-info-copyright">Text is available under the <a href="/wiki/Wikipedia:Text_of_the_Creative_Commons_Attribution-ShareAlike_4.0_International_License" title="Wikipedia:Text of the Creative Commons Attribution-ShareAlike 4.0 International License">Creative Commons Attribution-ShareAlike 4.0 License</a>; additional terms may apply. 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