CINXE.COM

<!DOCTYPE html> <html lang="en"> <head> <title>Entries beginning with X from FOLDOC</title> <meta http-equiv="Content-Security-Policy" content="default-src 'unsafe-inline' http: https:"> <meta name="verify-v1" content="siAI0ZOMn41hao0E/T76D1I2L3MtFjzE48P3ctCjRNU="> <meta charset="utf-8"> <meta name="viewport" content="width=device-width, initial-scale=1"> <meta name="msapplication-TileColor" content="#da532c"> <meta name="theme-color" content="#ffffff"> <meta name="google-translate-customization" content="828219db36930e1e-c51d915bf2ea717c-g9b503f9a85d5b5a7-a">  <script src="https://www.googletagmanager.com/gtag/js?id=UA-9715943-1"></script> <script> window.dataLayer = window.dataLayer || []; function gtag(){dataLayer.push(arguments);} gtag('js', new Date()); gtag('config', 'UA-9715943-1'); </script>  <link href="//fonts.googleapis.com/css?family=Duru+Sans%7CBelgrano%7CInconsolata%7CAlef%7CArmata" rel="stylesheet" type="text/css"> <link rel="stylesheet" type="text/css" href="/css/layout.css?2">  <link rel="apple-touch-icon" sizes="152x152" href="/im/apple-touch-icon.png"> <link rel="icon" type="image/png" sizes="32x32" href="/im/favicon-32x32.png"> <link rel="icon" type="image/png" sizes="16x16" href="/im/favicon-16x16.png"> <link rel="manifest" href="/im/site.webmanifest"> <link rel="mask-icon" href="/im/safari-pinned-tab.svg" color="#5bbad5"> <link rel="canonical" href="https://foldoc.org/contents/X.html"> <link rel="alternate" type="application/rss+xml" title="FOLDOC" href="/rss.xml"> <link rel="search" title="FOLDOC" type="application/opensearchdescription+xml" href="//foldoc.org/search.xml">  <script async src="https://pagead2.googlesyndication.com/pagead/js/adsbygoogle.js?client=ca-pub-5521724329338202" crossorigin="anonymous"></script>  </head> <body> <div id="fb-root"></div> <script> (function (d, s, id) { var js, fjs = d.getElementsByTagName(s)[0]; if (d.getElementById(id)) return; js = d.createElement(s); js.id = id; js.src = "//connect.facebook.net/en_GB/all.js#xfbml=1"; fjs.parentNode.insertBefore(js, fjs); }(document, 'script', 'facebook-jssdk')); </script> <div id="container"> <div id="left"> <a href="/"> <img src="/foldoc.gif" width="300" height="98" alt="Free On-line Dictionary of Computing" class="logo"> </a> <div id="nav"> <a href="/contents.html" class="button">Contents</a> <a href="/help.html" class="button">Help</a> <a href="/random-entry" class="button">Random</a> </div> <form action="/"> <input type="text" name="query" id="query" autofocus="autofocus"> <input type="submit" name="action" value="Search" class="button"> </form> <div id="content"> <h2>Entries beginning with X</h2> <p><div class="word-list"> <table> <tr><td><a href="/X">X</a></td><td><a href="/X-1">X-1</a></td><td><a href="/X11R4">X11R4</a></td></tr> <tr><td><a href="/X11R5">X11R5</a></td><td><a href="/X11R6">X11R6</a></td><td><a href="/X.12">X.12</a></td></tr> <tr><td><a href="/X2">X2</a></td><td><a href="/X.208">X.208</a></td><td><a href="/X.209">X.209</a></td></tr> <tr><td><a href="/X.21">X.21</a></td><td><a href="/X.214">X.214</a></td><td><a href="/X.215">X.215</a></td></tr> <tr><td><a href="/X.216">X.216</a></td><td><a href="/X.217">X.217</a></td><td><a href="/X.219">X.219</a></td></tr> <tr><td><a href="/X.224">X.224</a></td><td><a href="/X.225">X.225</a></td><td><a href="/X.226">X.226</a></td></tr> <tr><td><a href="/X.227">X.227</a></td><td><a href="/X.229">X.229</a></td><td><a href="/X.25">X.25</a></td></tr> <tr><td><a href="/X.28">X.28</a></td><td><a href="/X.29">X.29</a></td><td><a href="/X.3">X.3</a></td></tr> <tr><td><a href="/X3J16">X3J16</a></td><td><a href="/X3T10">X3T10</a></td><td><a href="/X.400">X.400</a></td></tr> <tr><td><a href="/X.409">X.409</a></td><td><a href="/X.500">X.500</a></td><td><a href="/X.680">X.680</a></td></tr> <tr><td><a href="/X.75">X.75</a></td><td><a href="/x86">x86</a></td><td><a href="/x86+processor+socket">x86 processor socket</a></td></tr> <tr><td><a href="/XA">XA</a></td><td><a href="/Xaw">Xaw</a></td><td><a href="/Xbase">Xbase</a></td></tr> <tr><td><a href="/xbeeb">xbeeb</a></td><td><a href="/xbm">xbm</a></td><td><a href="/XC">XC</a></td></tr> <tr><td><a href="/X+client">X client</a></td><td><a href="/X+Consortium">X Consortium</a></td><td><a href="/Xcoral">Xcoral</a></td></tr> <tr><td><a href="/xdbx">xdbx</a></td><td><a href="/X-Designer">X-Designer</a></td><td><a href="/X.desktop">X.desktop</a></td></tr> <tr><td><a href="/XDL">XDL</a></td><td><a href="/XDR">XDR</a></td><td><a href="/XDS+530">XDS 530</a></td></tr> <tr><td><a href="/XDS+940">XDS 940</a></td><td><a href="/xDSL">xDSL</a></td><td><a href="/Xemacs">Xemacs</a></td></tr> <tr><td><a href="/XENIX">XENIX</a></td><td><a href="/Xeon">Xeon</a></td><td><a href="/xerox">xerox</a></td></tr> <tr><td><a href="/XEROX+Corporation">XEROX Corporation</a></td><td><a href="/Xerox+Data+Systems+Model+530">Xerox Data Systems Model 530</a></td><td><a href="/Xerox+Data+Systems+Model+940">Xerox Data Systems Model 940</a></td></tr> <tr><td><a href="/XEROX+Network+Services">XEROX Network Services</a></td><td><a href="/Xerox+Network+System">Xerox Network System</a></td><td><a href="/XEROX+PARC">XEROX PARC</a></td></tr> <tr><td><a href="/Xerox+Star">Xerox Star</a></td><td><a href="/XFree86+Project,+Inc.">XFree86 Project, Inc.</a></td><td><a href="/XFS">XFS</a></td></tr> <tr><td><a href="/Xfun">Xfun</a></td><td><a href="/XGA">XGA</a></td><td><a href="/XGA-2">XGA-2</a></td></tr> <tr><td><a href="/XHTML">XHTML</a></td><td><a href="/Xi">Xi</a></td><td><a href="/XIE">XIE</a></td></tr> <tr><td><a href="/Xilinx,+Inc.">Xilinx, Inc.</a></td><td><a href="/Xilinx+Netlist+Format">Xilinx Netlist Format</a></td><td><a href="/X+Image+Extension">X Image Extension</a></td></tr> <tr><td><a href="/Xlib">Xlib</a></td><td><a href="/xlisp">xlisp</a></td><td><a href="/xls">xls</a></td></tr> <tr><td><a href="/XML">XML</a></td><td><a href="/xmlrpc.php">xmlrpc.php</a></td><td><a href="/XML+schema">XML schema</a></td></tr> <tr><td><a href="/XML+Template+Pages">XML Template Pages</a></td><td><a href="/XML+User-Interface+Language">XML User-Interface Language</a></td><td><a href="/XMM">XMM</a></td></tr> <tr><td><a href="/XMODEM">XMODEM</a></td><td><a href="/XMODEM-1K">XMODEM-1K</a></td><td><a href="/xmosaic">xmosaic</a></td></tr> <tr><td><a href="/XMS">XMS</a></td><td><a href="/XNF">XNF</a></td><td><a href="/xnf2ver">xnf2ver</a></td></tr> <tr><td><a href="/XNS">XNS</a></td><td><a href="/XOFF">XOFF</a></td><td><a href="/XON">XON</a></td></tr> <tr><td><a href="/XON/XOFF">XON/XOFF</a></td><td><a href="/Xopen">Xopen</a></td><td><a href="/X/Open">X/Open</a></td></tr> <tr><td><a href="/X/open+Portability+Guide">X/open Portability Guide</a></td><td><a href="/X/Open+System+Interface">X/Open System Interface</a></td><td><a href="/xor">xor</a></td></tr> <tr><td><a href="/XP">XP</a></td><td><a href="/XPC">XPC</a></td><td><a href="/XperCASE">XperCASE</a></td></tr> <tr><td><a href="/XPG">XPG</a></td><td><a href="/XPG3">XPG3</a></td><td><a href="/XPL">XPL</a></td></tr> <tr><td><a href="/xpm">xpm</a></td><td><a href="/XPOP">XPOP</a></td><td><a href="/XP+Pro">XP Pro</a></td></tr> <tr><td><a href="/Xpress+Transport+Protocol">Xpress Transport Protocol</a></td><td><a href="/X+protocol">X protocol</a></td><td><a href="/xref">xref</a></td></tr> <tr><td><a href="/XRemote">XRemote</a></td><td><a href="/XRN">XRN</a></td><td><a href="/XSB">XSB</a></td></tr> <tr><td><a href="/XScheme">XScheme</a></td><td><a href="/x-scm">x-scm</a></td><td><a href="/XSD">XSD</a></td></tr> <tr><td><a href="/X+server">X server</a></td><td><a href="/XSI">XSI</a></td><td><a href="/XSL">XSL</a></td></tr> <tr><td><a href="/XSLT">XSLT</a></td><td><a href="/XT">XT</a></td><td><a href="/Xt">Xt</a></td></tr> <tr><td><a href="/XT+bus+architecture">XT bus architecture</a></td><td><a href="/xterm">xterm</a></td><td><a href="/X+terminal">X terminal</a></td></tr> <tr><td><a href="/XTI">XTI</a></td><td><a href="/XTP">XTP</a></td><td><a href="/XTP+Forum">XTP Forum</a></td></tr> <tr><td><a href="/XTRAN">XTRAN</a></td><td><a href="/XUI">XUI</a></td><td><a href="/XUL">XUL</a></td></tr> <tr><td><a href="/Xv%2b%2b">Xv++</a></td><td><a href="/XVGA">XVGA</a></td><td><a href="/XView">XView</a></td></tr> <tr><td><a href="/XVT">XVT</a></td><td><a href="/X-Windows">X-Windows</a></td><td><a href="/X+Window+System">X Window System</a></td></tr> <tr><td><a href="/XWIP">XWIP</a></td><td><a href="/xxgdb">xxgdb</a></td><td><a href="/XXX">XXX</a></td></tr> <tr><td><a href="/Xy-pic">Xy-pic</a></td><td><a href="/xyzzy">xyzzy</a></td><td> </td></tr> </table> </div></p> <p class="vertical-space"></p> <hr> <div></div> <hr>  <div id="HCB_comment_box">Loading</div> <link rel="stylesheet" type="text/css" href="//www.htmlcommentbox.com/static/skins/bootstrap/twitter-bootstrap.css?v=0"> <script language="javascript" id="hcb"> hcb_user = { PAGE: 'https://foldoc.org/contents/X.html', comments_header: ' ', no_comments_msg: ' ', err_comment_empty: 'Your comment was not posted because it was empty!', rss: '', }; var s = document.createElement("script"); s.setAttribute("type", "text/javascript"); s.setAttribute("src", "//www.htmlcommentbox.com/jread?page=" + escape(hcb_user.PAGE).replace(/\+/g, "%2B") + "&mod=%241%24wq1rdBcg%24.0y2uzvjA2bsnhzpXVq9F." + "&opts=17374&num=10"); // No e-mail field: 16846 if (typeof s != "undefined") document.getElementsByTagName("head")[0].appendChild(s); </script> <script> setTimeout(function () { document.getElementById('hcb_form_content').rows = 1 }, 1000); </script> <hr>  </div>  </div>  <div id="right"> <div id="google_translate_element"> <script> function googleTranslateElementInit() { new google.translate.TranslateElement({ pageLanguage: 'en' }, 'google_translate_element'); } </script> <script src="https://translate.google.com/translate_a/element.js?cb=googleTranslateElementInit"></script> </div> <p><br></p> <hr> <div id="social"> <div class="fb-like" data-href="http://foldoc.org/" data-layout="button_count" data-action="like" data-show-faces="false" data-share="true"> </div> <a href="https://twitter.com/share" class="twitter-share-button" data-via="foldoc"> Tweet </a> <script> if (!document.getElementById('twitter-wjs')) { var fjs = document.getElementsByTagName('script')[0], js = document.createElement('script'); js.id = 'twitter-wjs'; js.src = 'https://platform.twitter.com/widgets.js'; fjs.parentNode.insertBefore(js, fjs); } </script> </div> <hr> <div> <p></p> </div> <p> <a href="/rss.xml"> <img src="/orangerss.gif" width="14" height="14" alt="RSS feed of new items"> </a>   <a href="/new.html">Recent Updates</a>     |     <a href="/missing.html">Missing Terms</a> </p> <p>Updated: Sat, 05 Apr 2025 21:25:48 GMT</p> <p>15282 entries</p> <p><em><a href="/Free+On-line+Dictionary">Copyright Denis Howe 1985</a></em></p> </div>  </div>   <script type="text/javascript"> window._qevents = window._qevents || []; (function() { var elem = document.createElement('script'); elem.src = 'https://secure.quantserve.com/quant.js'; elem.async = true; elem.type = 'text/javascript'; var scpt = document.getElementsByTagName('script')[0]; scpt.parentNode.insertBefore(elem, scpt); })(); window._qevents.push({ qacct: 'p-48Rosdvs3EiOc', uid: '__INSERT_EMAIL_HERE__' }); </script> <noscript> <div style="display:none;"> <img src="https//pixel.quantserve.com/pixel/p-48Rosdvs3EiOc.gif" border="0" height="1" width="1" alt="Quantcast"/> </div> </noscript>  </body> </html>