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Unsourced material may be challenged and removed.<br /><small><span class="plainlinks"><i>Find sources:</i> <a rel="nofollow" class="external text" href="https://www.google.com/search?as_eq=wikipedia&q=%22EKA2%22">"EKA2"</a> – <a rel="nofollow" class="external text" href="https://www.google.com/search?tbm=nws&q=%22EKA2%22+-wikipedia&tbs=ar:1">news</a> <b>·</b> <a rel="nofollow" class="external text" href="https://www.google.com/search?&q=%22EKA2%22&tbs=bkt:s&tbm=bks">newspapers</a> <b>·</b> <a rel="nofollow" class="external text" href="https://www.google.com/search?tbs=bks:1&q=%22EKA2%22+-wikipedia">books</a> <b>·</b> <a rel="nofollow" class="external text" href="https://scholar.google.com/scholar?q=%22EKA2%22">scholar</a> <b>·</b> <a rel="nofollow" class="external text" href="https://www.jstor.org/action/doBasicSearch?Query=%22EKA2%22&acc=on&wc=on">JSTOR</a></span></small></span> <span class="date-container"><i>(<span class="date">May 2007</span>)</i></span><span class="hide-when-compact"><i> (<small><a href="/wiki/Help:Maintenance_template_removal" title="Help:Maintenance template removal">Learn how and when to remove this message</a></small>)</i></span></div></td></tr></tbody></table> <div class="shortdescription nomobile noexcerpt noprint searchaux" style="display:none">Operating system</div> <style data-mw-deduplicate="TemplateStyles:r1257001546">.mw-parser-output .infobox-subbox{padding:0;border:none;margin:-3px;width:auto;min-width:100%;font-size:100%;clear:none;float:none;background-color:transparent}.mw-parser-output .infobox-3cols-child{margin:auto}.mw-parser-output .infobox .navbar{font-size:100%}@media screen{html.skin-theme-clientpref-night .mw-parser-output .infobox-full-data:not(.notheme)>div:not(.notheme)[style]{background:#1f1f23!important;color:#f8f9fa}}@media screen and (prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .infobox-full-data:not(.notheme) div:not(.notheme){background:#1f1f23!important;color:#f8f9fa}}@media(min-width:640px){body.skin--responsive .mw-parser-output .infobox-table{display:table!important}body.skin--responsive .mw-parser-output .infobox-table>caption{display:table-caption!important}body.skin--responsive .mw-parser-output .infobox-table>tbody{display:table-row-group}body.skin--responsive .mw-parser-output .infobox-table tr{display:table-row!important}body.skin--responsive .mw-parser-output .infobox-table th,body.skin--responsive .mw-parser-output .infobox-table td{padding-left:inherit;padding-right:inherit}}</style><table class="infobox vevent"><caption class="infobox-title summary">EKA2</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"><a href="/wiki/Psion_(company)" title="Psion (company)">Psion</a><br /><a href="/wiki/Symbian_Ltd." class="mw-redirect" title="Symbian Ltd.">Symbian Ltd.</a><br /><a href="/wiki/Symbian_Foundation" title="Symbian Foundation">Symbian Foundation</a><br /><a href="/wiki/Nokia" title="Nokia">Nokia</a><br /><a href="/wiki/Accenture" title="Accenture">Accenture</a></td></tr><tr><th scope="row" class="infobox-label" style="white-space: nowrap;"><a href="/wiki/Programming_language" title="Programming language">Written in</a></th><td class="infobox-data"><a href="/wiki/Assembly_language" title="Assembly language">Assembly language</a>, <a href="/wiki/C_(programming_language)" title="C (programming language)">C</a>, then <a href="/wiki/C%2B%2B" title="C++">C++</a></td></tr><tr><th scope="row" class="infobox-label" style="white-space: nowrap;">OS family</th><td class="infobox-data"><a href="/wiki/EPOC_(operating_system)" title="EPOC (operating system)">EPOC</a> (<a href="/wiki/Symbian" title="Symbian">Symbian</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"><a href="/wiki/Proprietary_software" title="Proprietary software">Proprietary</a> and <a href="/wiki/Open-source_software" title="Open-source software">Open source</a></td></tr><tr><th scope="row" class="infobox-label" style="white-space: nowrap;">Initial release</th><td class="infobox-data">2005<span class="noprint">; 19 years ago</span><span style="display:none"> (<span class="bday dtstart published updated">2005</span>)</span></td></tr><tr><th scope="row" class="infobox-label" style="white-space: nowrap;"><a href="/wiki/Software_release_life_cycle" title="Software release life cycle">Final release</a></th><td class="infobox-data">10.1 / October 2, 2012<span class="noprint">; 12 years ago</span><span style="display:none"> (<span class="bday dtstart published updated">2012-10-02</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/Mobile_phone" title="Mobile phone">Mobile phones</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/ARM_architecture" class="mw-redirect" title="ARM architecture">ARM</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> <a href="/wiki/Real-time_operating_system" title="Real-time operating system">Real-time</a></td></tr><tr><th scope="row" class="infobox-label" style="white-space: nowrap;"><a href="/wiki/Software_license" title="Software license">License</a></th><td class="infobox-data"><a href="/wiki/Eclipse_Public_License" title="Eclipse Public License">Eclipse Public</a></td></tr><tr><th scope="row" class="infobox-label" style="white-space: nowrap;">Preceded by</th><td class="infobox-data"><a href="/wiki/EKA1" title="EKA1">EKA1</a></td></tr><tr><th scope="row" class="infobox-label" style="white-space: nowrap;">Official website</th><td class="infobox-data"><span class="url"><a rel="nofollow" class="external text" href="http://developer.symbian.org/wiki/index.php/Category:Kernel_&_Hardware_Services">developer<wbr />.symbian<wbr />.org<wbr />/wiki<wbr />/index<wbr />.php<wbr />/Category:Kernel<wbr />_&<wbr />_Hardware<wbr />_Services</a></span></td></tr></tbody></table> <p><b>EKA2</b> (<b>EPOC Kernel Architecture 2</b>) is the second-generation <a href="/wiki/Symbian" title="Symbian">Symbian</a> platform <a href="/wiki/Real-time_operating_system" title="Real-time operating system">real-time operating system</a> <a href="/wiki/Kernel_(operating_system)" title="Kernel (operating system)">kernel</a>,<sup id="cite_ref-aboutcomnov_1-0" class="reference"><a href="#cite_note-aboutcomnov-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup> which originated in the earlier operating system <a href="/wiki/EPOC_(operating_system)" title="EPOC (operating system)">EPOC</a>. </p><p>EKA2 began with a <a href="/wiki/Proprietary_software" title="Proprietary software">proprietary software</a> license. In October 2009, it was released as <a href="/wiki/Free_and_open-source_software" title="Free and open-source software">free and open-source software</a> under an <a href="/wiki/Eclipse_Public_License" title="Eclipse Public License">Eclipse Public License</a>.<sup id="cite_ref-2" class="reference"><a href="#cite_note-2"><span class="cite-bracket">[</span>2<span class="cite-bracket">]</span></a></sup> In April 2011, it was reverted to a proprietary license. </p><p>Like its predecessor, <a href="/wiki/EKA1" title="EKA1">EKA1</a>, it has <a href="/wiki/Preemption_(computing)" title="Preemption (computing)">preemptive</a> multithreading and full memory protection. The main differences are: </p> <ul><li><a href="/wiki/Real-time_computing" title="Real-time computing">Real-time</a> guarantees: each application programming interface (<a href="/wiki/API" title="API">API</a>) call is fast, but more importantly, time-bound</li> <li>Multiple <a href="/wiki/Thread_(computing)" title="Thread (computing)">threads</a> inside the kernel, and outside</li> <li>Pluggable <a href="/wiki/Memory_model_(programming)" title="Memory model (programming)">memory models</a>, allowing better support for later generations of <a href="/wiki/ARM_architecture" class="mw-redirect" title="ARM architecture">ARM</a> <a href="/wiki/Instruction_set_architecture" title="Instruction set architecture">instruction set architecture</a>.</li> <li>A <i>nanokernel</i> which provides the most basic OS facilities upon which other <i>personality layers</i> can be built</li></ul> <p>The <a href="/wiki/User_interface" title="User interface">user interface</a> of EKA2 is almost fully compatible with EKA1. EKA1 was not used after Symbian OS version 8.1, and was superseded in 2005. </p><p>The main advantage of EKA2 was its ability to run full telephone signalling <a href="/wiki/Protocol_stack" title="Protocol stack">protocol stacks</a>. Previously, on Symbian phones, these had to run on a separate <a href="/wiki/Central_processing_unit" title="Central processing unit">central processing unit</a> (CPU). Such signalling stacks are very complex and rewriting them to work natively on Symbian OS is typically not an option.<sup class="noprint Inline-Template Template-Fact" style="white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Citation_needed" title="Wikipedia:Citation needed"><span title="This claim needs references to reliable sources. (August 2011)">citation needed</span></a></i>]</sup> EKA2 thus allows <i>personality layers</i> to emulate the basic primitives of other operating systems, thus allowing existing signalling stacks to run largely unchanged. </p><p>Real-time guarantees are a prerequisite of signalling stacks, and also help with multimedia tasks. However, as with any RTOS, a full analysis of all threads is needed before any real-time guarantees can be offered to anything except the highest-priority thread; because higher priority threads may prevent lower-priority threads from running. Any multimedia task is likely to involve graphics, storage and/or networking activity, all of which are more likely to disrupt the stream than the kernel is. </p><p>Inside the kernel, EKA1 only allowed one thread (plus a <i>null</i> idle thread). EKA2 allows many threads. This makes it much easier to write <a href="/wiki/Device_driver" title="Device driver">device drivers</a> that involve complex <a href="/wiki/Finite-state_machine" title="Finite-state machine">finite-state machines</a>, such as those for <a href="/wiki/SD_card" title="SD card">SD card</a> memory sticks or <a href="/wiki/USB_flash_drive" title="USB flash drive">USB flash drives</a>. Interrupts are handled with an <a href="/wiki/Interrupt_service_routine" class="mw-redirect" title="Interrupt service routine">interrupt service routine</a>, which may request an <i>immediate deferred function call</i> (called as soon as the interrupts are processed), or a <i>deferred function call</i>, which is queued to run on a kernel thread. Either may in turn communicate with user-side threads. </p><p>Power management in EKA2 was largely unchanged from EKA1. The exact scheme varies between phones, but generally the null thread puts the CPU and <a href="/wiki/Peripheral" title="Peripheral">peripherals</a> to sleep, after having requested a wake-up whenever the next timer is due to expire. </p><p>EKA2 runs on <a href="/wiki/ARM_architecture" class="mw-redirect" title="ARM architecture">ARM architecture</a> CPUs and the <i>WINS</i> emulator. Unofficial ports exist for other CPUs. On the emulator, EKA2 provides somewhat better emulation than EKA1, more so for the <code class="mw-highlight mw-highlight-lang-text mw-content-ltr" style="" dir="ltr">RProcess</code> APIs which Symbian OS uses to represent <a href="/wiki/Process_(computing)" title="Process (computing)">processes</a>. In EKA1 they didn't work at all on the emulator, which runs as a single Windows process. </p><p>Much of the credit for EKA2 goes to a single Symbian kernel engineer, who began the project as an experiment many years before it became an official part of Symbian OS.<sup id="cite_ref-3" class="reference"><a href="#cite_note-3"><span class="cite-bracket">[</span>3<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading2"><h2 id="See_also">See also</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=EKA2&action=edit&section=1" title="Edit section: See also"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <style data-mw-deduplicate="TemplateStyles:r1259569809">.mw-parser-output .portalbox{padding:0;margin:0.5em 0;display:table;box-sizing:border-box;max-width:175px;list-style:none}.mw-parser-output .portalborder{border:1px solid var(--border-color-base,#a2a9b1);padding:0.1em;background:var(--background-color-neutral-subtle,#f8f9fa)}.mw-parser-output .portalbox-entry{display:table-row;font-size:85%;line-height:110%;height:1.9em;font-style:italic;font-weight:bold}.mw-parser-output .portalbox-image{display:table-cell;padding:0.2em;vertical-align:middle;text-align:center}.mw-parser-output .portalbox-link{display:table-cell;padding:0.2em 0.2em 0.2em 0.3em;vertical-align:middle}@media(min-width:720px){.mw-parser-output .portalleft{clear:left;float:left;margin:0.5em 1em 0.5em 0}.mw-parser-output .portalright{clear:right;float:right;margin:0.5em 0 0.5em 1em}}</style><ul role="navigation" aria-label="Portals" class="noprint portalbox portalborder portalright"> <li class="portalbox-entry"><span class="portalbox-image"><span class="noviewer" typeof="mw:File"><span><img alt="" src="//upload.wikimedia.org/wikipedia/commons/thumb/3/31/Free_and_open-source_software_logo_%282009%29.svg/28px-Free_and_open-source_software_logo_%282009%29.svg.png" decoding="async" width="28" height="28" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/3/31/Free_and_open-source_software_logo_%282009%29.svg/42px-Free_and_open-source_software_logo_%282009%29.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/3/31/Free_and_open-source_software_logo_%282009%29.svg/56px-Free_and_open-source_software_logo_%282009%29.svg.png 2x" data-file-width="512" data-file-height="512" /></span></span></span><span class="portalbox-link"><a href="/wiki/Portal:Free_and_open-source_software" title="Portal:Free and open-source software">Free and open-source software portal</a></span></li></ul> <ul><li><a href="/wiki/Nanokernel" class="mw-redirect" title="Nanokernel">Nanokernel</a></li></ul> <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=EKA2&action=edit&section=2" 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-aboutcomnov-1"><span class="mw-cite-backlink"><b><a href="#cite_ref-aboutcomnov_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 class="citation web cs1"><a rel="nofollow" class="external text" href="https://web.archive.org/web/20110121072523/http://wiki.forum.nokia.com/index.php/Symbian_OS_Internals">"Symbian OS Internals"</a>. Archived from <a rel="nofollow" class="external text" href="http://wiki.forum.nokia.com/index.php/Symbian_OS_Internals">the original</a> on 2011-01-21<span class="reference-accessdate">. Retrieved <span class="nowrap">2011-05-04</span></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=Symbian+OS+Internals&rft_id=http%3A%2F%2Fwiki.forum.nokia.com%2Findex.php%2FSymbian_OS_Internals&rfr_id=info%3Asid%2Fen.wikipedia.org%3AEKA2" class="Z3988"></span></span> </li> <li id="cite_note-2"><span class="mw-cite-backlink"><b><a href="#cite_ref-2">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFBlandford2009" class="citation web cs1">Blandford, Rafe (October 22, 2009). <a rel="nofollow" class="external text" href="http://www.allaboutsymbian.com/news/item/10641_Symbian_Foundation_opensources.php">"Symbian Foundation opensources EKA2 microkernel"</a>. <i>All About Symbian</i>. Symbian Foundation.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=All+About+Symbian&rft.atitle=Symbian+Foundation+opensources+EKA2+microkernel&rft.date=2009-10-22&rft.aulast=Blandford&rft.aufirst=Rafe&rft_id=http%3A%2F%2Fwww.allaboutsymbian.com%2Fnews%2Fitem%2F10641_Symbian_Foundation_opensources.php&rfr_id=info%3Asid%2Fen.wikipedia.org%3AEKA2" class="Z3988"></span></span> </li> <li id="cite_note-3"><span class="mw-cite-backlink"><b><a href="#cite_ref-3">^</a></b></span> <span class="reference-text"><a rel="nofollow" class="external text" href="http://uk.linkedin.com/in/dennismayeka2">Dennis May - United Kingdom | LinkedIn</a>. Uk.linkedin.com. Retrieved on 2013-12-09.</span> </li> </ol></div></div> <div class="mw-heading mw-heading2"><h2 id="External_links">External links</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=EKA2&action=edit&section=3" title="Edit section: External links"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <ul><li><a rel="nofollow" class="external free" href="https://web.archive.org/web/20091025051019/http://developer.symbian.org/wiki/index.php/Category%3AKernel_%26_Hardware_Services">https://web.archive.org/web/20091025051019/http://developer.symbian.org/wiki/index.php/Category%3AKernel_%26_Hardware_Services</a></li> <li><a rel="nofollow" class="external free" href="https://web.archive.org/web/20090717151501/http://wiki.forum.nokia.com/index.php/EPOC_Kernel_Architecture_2">https://web.archive.org/web/20090717151501/http://wiki.forum.nokia.com/index.php/EPOC_Kernel_Architecture_2</a></li> <li><a rel="nofollow" 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Organiser">Organiser I</a> (1984)</li> <li><a href="/wiki/Psion_Organiser#Organiser_II" title="Psion Organiser">Organiser II</a> (1986)</li></ul></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Clamshell_design" title="Clamshell design">Clamshell designs</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/Psion_Series_3" title="Psion Series 3">Psion Series 3</a> (1991) <ul><li><a href="/wiki/Psion_Siena" title="Psion Siena">Psion Siena</a> (1996)</li></ul></li> <li><a href="/wiki/Psion_Series_5" title="Psion Series 5">Psion Series 5</a> (1997)</li> <li><a href="/wiki/Psion_Revo" title="Psion Revo">Psion Revo</a> (1999)</li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Subnotebook" title="Subnotebook">Subnotebooks</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/Psion_netBook" title="Psion netBook">Psion netBook</a> (1999)</li> <li><a href="/wiki/Psion_Series_7" title="Psion Series 7">Psion Series 7</a> (2000)</li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Laptop" title="Laptop">Laptops</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/Psion_MC_series" class="mw-redirect" title="Psion MC series">Psion MC series</a> (1989): MC200, MC400, MC400 Word, MC600 DOS</li></ul> </div></td></tr></tbody></table><div></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Software" title="Software">Software</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 id="Operatingsystems" 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 id="Kernels" 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"> <ul><li><a href="/wiki/EKA1" title="EKA1">EKA1</a> (1989)</li> <li><i><a class="mw-selflink selflink">EKA2</a></i>^° (2005)</li></ul> </div></td></tr></tbody></table><div> <ul><li><a href="/wiki/EPOC_(operating_system)" title="EPOC (operating system)">EPOC</a> <ul><li><a href="/wiki/EPOC_(operating_system)#EPOC16_(1989–1998)" title="EPOC (operating system)">EPOC16–SIBO</a> (1989)</li> <li><i><a href="/wiki/EPOC_(operating_system)#EPOC32_(1997–2000)" title="EPOC (operating system)">EPOC32</a></i> (1997)</li></ul></li> <li><i><a href="/wiki/Symbian" title="Symbian">Symbian</a></i>^° OS (1997) (<a href="/wiki/Graphical_user_interface" title="Graphical user interface">GUIs</a>: <a href="/wiki/MOAP" title="MOAP">MOAP</a>(S) (2001), <a href="/wiki/S60_(software_platform)" title="S60 (software platform)">S60</a> (2001), <a href="/wiki/UIQ" title="UIQ">UIQ</a> (2002))</li></ul></div></td></tr></tbody></table><div> <ul><li><a href="/wiki/Open_Programming_Language" title="Open Programming Language">Open Programming Language</a>, OPL (1984)</li></ul></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Organisations</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><td colspan="2" class="navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <li><a href="/wiki/Psion_(company)" title="Psion (company)">Psion</a> (1980)</li> <li><a href="/wiki/Symbian_Software" title="Symbian Software">Symbian Software</a> (1998) (<a href="/wiki/UIQ_Technology" title="UIQ Technology">UIQ Technology</a> (1999), <a href="/wiki/Symbian_Foundation" title="Symbian Foundation">Symbian Foundation</a> (2008))</li> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Executives</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/Nigel_Clifford" title="Nigel Clifford">Nigel Clifford</a> (Symbian)</li> <li><a href="/wiki/David_Levin_(businessman)" title="David Levin (businessman)">David Levin</a> (Psion, Symbian)</li></ul> </div></td></tr></tbody></table><div></div></td></tr><tr><td class="navbox-abovebelow" colspan="2"><div> <ul><li><i>italics</i> <b>= <a href="/wiki/Microkernel" title="Microkernel">Microkernel</a></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:Psion_devices" title="Category:Psion devices">Category: Psion devices</a></b></li></ul> </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-nanokernels" 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-nanokernels" 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 class="mw-selflink selflink">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 href="/wiki/Vanguard_(microkernel)" title="Vanguard (microkernel)">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-like" 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 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="Real-time_operating_systems_(RTOS)" 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:Real-time_operating_systems" title="Template:Real-time operating systems"><abbr title="View this template">v</abbr></a></li><li class="nv-talk"><a href="/wiki/Template_talk:Real-time_operating_systems" title="Template talk:Real-time operating systems"><abbr title="Discuss this template">t</abbr></a></li><li class="nv-edit"><a href="/wiki/Special:EditPage/Template:Real-time_operating_systems" title="Special:EditPage/Template:Real-time operating systems"><abbr title="Edit this template">e</abbr></a></li></ul></div><div id="Real-time_operating_systems_(RTOS)" style="font-size:114%;margin:0 4em"><a href="/wiki/Real-time_operating_system" title="Real-time operating system">Real-time operating systems</a> (RTOS)</div></th></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"> <ul><li><i><a href="/wiki/DNIX" title="DNIX">DNIX</a></i></li> <li><a href="/wiki/Junos_OS" title="Junos OS">Junos OS</a></li> <li><a href="/wiki/LynxOS" title="LynxOS">LynxOS</a></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/Real-Time_Linux" class="mw-redirect" title="Real-Time Linux">Real-Time Linux</a>°</li> <li><a href="/wiki/RTLinux" title="RTLinux">RTLinux</a>°</li> <li><i><a href="/wiki/UNOS_(operating_system)" title="UNOS (operating system)">UNOS</a></i></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/LiteOS" title="LiteOS">LiteOS</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/LiteOS" title="LiteOS">LiteOS</a></i>°</li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Partial</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/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">Operating System Embedded</a>^ (OSE)</li> <li><a href="/wiki/PX5_RTOS" title="PX5 RTOS">PX5 RTOS</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/TRON_project" title="TRON project">TRON</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><td colspan="2" class="navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/ITRON_project" title="ITRON project">ITRON project</a></li> <li><a href="/wiki/T-Kernel" title="T-Kernel">T-Kernel</a> <ul><li><a href="/wiki/Micro_T-Kernel" title="Micro T-Kernel">Micro T-Kernel</a></li> <li><a href="/wiki/T-Engine_Forum" title="T-Engine Forum">T-Engine Forum</a> (organization)</li> <li><a href="/wiki/T-License" title="T-License">T-License</a></li></ul></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Partial</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/ECos" title="ECos">eCos</a>°</li> <li><a href="/wiki/RTEMS" title="RTEMS">RTEMS</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-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><i><a href="/wiki/EROS_(microkernel)" title="EROS (microkernel)">EROS</a></i>^°</li> <li><a href="/wiki/SeL4" class="mw-redirect" title="SeL4">seL4</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#Chorus/Jazz" title="JavaOS">Chorus/Jazz</a></i>^ (<i><a href="/wiki/JavaOS" title="JavaOS">JavaOS</a></i> + <i><a href="/wiki/ChorusOS" title="ChorusOS">ChorusOS</a></i>^)</li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/DOS" title="DOS">DOS</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/Multiuser_DOS" title="Multiuser DOS">Multiuser DOS</a></i> <ul><li><i><a href="/wiki/Concurrent_DOS" class="mw-redirect" title="Concurrent DOS">Concurrent DOS</a></i></li> <li><i><a href="/wiki/FlexOS" title="FlexOS">FlexOS</a></i></li> <li><i><a href="/wiki/REAL/32" class="mw-redirect" title="REAL/32">REAL/32</a></i></li></ul></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-odd" 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/Psion_(company)" title="Psion (company)">Psion</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 class="mw-selflink selflink">EKA2</a></i>^° kernel → <i><a href="/wiki/Symbian" title="Symbian">Symbian</a> OS</i>^°</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/ThreadX" title="ThreadX">ThreadX</a>^</li> <li><a href="/wiki/Windows_Embedded_Compact" title="Windows Embedded Compact">Windows Embedded Compact</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/IBM" title="IBM">IBM</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/4680_OS" class="mw-redirect" title="4680 OS">4680 OS</a></i></li> <li><i><a href="/wiki/4690_Operating_System" title="4690 Operating System">4690 OS</a></i></li> <li><a href="/wiki/Transaction_Processing_Facility" title="Transaction Processing Facility">Transaction Processing Facility</a> (TPF)</li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Texas_Instruments" title="Texas Instruments">Texas Instruments</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/DSOS" title="DSOS">DSOS</a></i></li> <li><a href="/wiki/TI-RTOS#RTOS_kernel_overview" title="TI-RTOS">TI-RTOS Kernel</a>^°</li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Digital_Equipment_Corporation" title="Digital Equipment Corporation">DEC</a> <a href="/wiki/PDP-11" title="PDP-11">PDP-11</a> <a href="/wiki/VAX" title="VAX">VAX</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/RSX-11" title="RSX-11">RSX-11</a></i></li> <li><i><a href="/wiki/RT-11" title="RT-11">RT-11</a></i></li> <li><i><a href="/wiki/VAXELN" title="VAXELN">VAXELN</a></i></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Low resource</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/ChibiOS/RT" title="ChibiOS/RT">ChibiOS/RT</a>^°</li> <li><a href="/wiki/Contiki" title="Contiki">Contiki</a>°</li> <li><a href="/wiki/ERIKA_Enterprise" title="ERIKA Enterprise">ERIKA Enterprise</a>°</li> <li>FunkOS°</li> <li><a href="/wiki/Apache_Mynewt" title="Apache Mynewt">Mynewt</a>°</li> <li><i><a href="/wiki/Nano-RK" title="Nano-RK">Nano-RK</a></i>°</li> <li><a href="/wiki/OpenComRTOS" title="OpenComRTOS">OpenComRTOS</a>^</li> <li><a href="/wiki/PX5_RTOS" title="PX5 RTOS">PX5 RTOS</a>^</li> <li><a href="/wiki/RT-Thread" title="RT-Thread">RT-Thread</a>° Nano</li> <li><a href="/wiki/RIOT_(operating_system)" title="RIOT (operating system)">RIOT</a>°</li> <li><a href="/wiki/ThreadX" title="ThreadX">ThreadX</a>^</li> <li><a href="/wiki/Zephyr_(operating_system)" title="Zephyr (operating system)">Zephyr</a>^°</li></ul> </div></td></tr></tbody></table><div> <ul><li><i><a href="/wiki/BeRTOS" title="BeRTOS">BeRTOS</a></i>^°</li> <li><i><a href="/wiki/DioneOS" title="DioneOS">DioneOS</a></i></li> <li><a href="/wiki/Segger_Microcontroller_Systems" title="Segger Microcontroller Systems">embOS</a></li> <li><a href="/wiki/FreeRTOS" title="FreeRTOS">FreeRTOS</a>^°</li> <li><a href="/wiki/Micro-Controller_Operating_Systems" title="Micro-Controller Operating Systems">µC/OS</a>^°</li> <li><a href="/wiki/Green_Hills_Software#Real-time_operating_systems" title="Green Hills Software">µ-velOSity</a>^</li> <li><a href="/wiki/MQX" title="MQX">MQX</a>^</li> <li><a href="/wiki/OS-9" title="OS-9">OS-9</a> (<a href="/wiki/Microware" title="Microware">Microware</a>)</li> <li><a href="/wiki/Phantom_OS" title="Phantom OS">Phantom OS</a>^°</li> <li><i><a href="/wiki/PSOS_(real-time_operating_system)" title="PSOS (real-time operating system)">pSOS</a></i></li> <li><i><a href="/wiki/RMX_(operating_system)" title="RMX (operating system)">RMX</a></i></li> <li><a href="/wiki/RT-Thread" title="RT-Thread">RT-Thread</a>° Standard</li> <li><a href="/wiki/ScreenOS" title="ScreenOS">ScreenOS</a></li> <li><i><a href="/wiki/Sintran_III" title="Sintran III">Sintran III</a></i></li> <li><i><a href="/wiki/THEOS" title="THEOS">THEOS</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>^</li> <li><a href="/wiki/Versatile_Real-Time_Executive" title="Versatile Real-Time Executive">VRTX</a>^</li> <li><a href="/wiki/VxWorks" title="VxWorks">VxWorks</a></li> <li><a href="/wiki/EulerOS" title="EulerOS">UniProton</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-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <li><a href="/wiki/Robot_Operating_System" title="Robot Operating System">Robot Operating System</a>° 2</li> <li><a href="/wiki/RTAI" title="RTAI">RTAI</a>°</li> <li><a href="/wiki/TI-RTOS" title="TI-RTOS">TI-RTOS</a>^°</li> <li><a href="/wiki/Xenomai" title="Xenomai">Xenomai</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-odd" 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/David_Cheriton" title="David Cheriton">David Cheriton</a></li> <li><a href="/wiki/Dave_Cutler" title="Dave Cutler">Dave Cutler</a></li> <li><a href="/wiki/Dan_Dodge" title="Dan Dodge">Dan Dodge</a></li> <li><a href="/wiki/Adam_Dunkels" title="Adam Dunkels">Adam Dunkels</a></li> <li><a href="/wiki/Ken_Sakamura" title="Ken Sakamura">Ken Sakamura</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/Microkernel" title="Microkernel">Microkernel</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="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" 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