hCard microformat Validator (beta, of course)

This is an unofficial validator¹/conformance checker of the hCard microformat.

Po polsku
(translations welcome!)

Input

URL

Check entire XHTML or HTML page by entering its HTTP URL.

Fragment

Paste well-formed XHTML fragment or complete document containing hCard.

Upload

Upload HTML or XHTML file to validate it. For this to work your browser must be setting MIME types properly.

Example

If searching for hCards in the wild is tiring, check one of the test-cases:

Browse examples

API & Other

Any page by Referer

<a href="http://en.hcard.geekhood.net/referrer/">Validate hCards</a>

Bookmarklet

hCard?

RESTful JSON API

Send GET request to http://en.hcard.geekhood.net/?url=URL to validate&output=json.

Output will be roughly compatible with the Validator.nu JSON API. Likely to change in the future.

Please use this API for validation, not just as an converter/extraction tool.

Send Feedback

You can send feedback via e-mail or the form below.

If you're reporting a bug or have a suggestion, don't forget to include example hCard code.

Result

Congratulations! No errors found.

  1. No issues found.

    Card source 
    #hcard-Alexander-Willner
    Address Street 
    Bornheimer Str. 39
    City 
    Bonn
    Postcode 
    53111
    Country 
    Germany
    GEO latitude 
    50.73701
    longitude 
    7.08726
    Formatted name 
    Alexander Willner
    Name Given Name 
    Alexander
    Family Name 
    Willner
    Honorific Suffix 
    M. Sc.
    Nickname 
    Alex
    Photo URL http://chart.apis.google.com/chart?chs=64x64&cht=qr&choe=UTF-8&chl=MECARD:N:Alexander%20Willner;ADR:Bornheimer%20Str.%2039%2C%2053111%20Bonn%2C%20Germany;TEL:%2B491784580614;EMAIL:alex@willner.ws;URL:http://alex.willner.ws;BDAY:19800930;NICKNAME:Alex;;
    Telephone type 
    Cell
    value 
    +491784580614
    Telephone type 
    Fax
    value 
    +4922892985593
    URL http://alex.willner.ws

File source

<!DOCTYPE html><html lang="en"><head><meta charset="utf-8" /><meta name="viewport" content="width=800" /><meta name="robots" content="index,follow,noarchive" /><meta name="author" content="Alexander Willner" /><meta name="description" content="Official business card of reserach assistant Alexander Willner." /><meta name="keywords" content="alexander,alex,willner,alexander willner,xhtml,css,standards,hcard,w3c,html5" /><title>Alexander Willner | Business Card</title><link rel="me" href="http://alex.willner.ws/" /><link rel="openid.server" href="http://www.myopenid.com/server" /><link rel="openid.delegate" href="http://id.willner.ws/alex" /><link rel="openid2.local_id" href="http://id.willner.ws/alex" /><link rel="openid2.provider" href="http://www.myopenid.com/server" /><link rel="profile" href="http://microformats.org/profile/hcard" /><link rel="profile" href="http://gmpg.org/xfn/11" /><link rel="stylesheet" type="text/css" href="css/master.css" /><link rel="shortcut icon" href="favicon.ico" /><link rel="icon" href="favicon.ico" /><link rel="meta" type="application/rdf+xml" title="vCARD" href="http://microform.at/?type=hcard-rdf&amp;url=http%3A%2F%2Falex.willner.ws" /><link rel="meta" type="application/rdf+xml" title="FOAF" href="http://microform.at/?type=hfoaf&amp;url=http%3A%2F%2Falex.willner.ws" /> </head><body><!--START BODY--><address class="email skip">Author:<a href="mailto:alex&#064;willner.ws">Alexander Willner</a></address><div id="container"><!--START CONTAINER--><header><div class="header"><!--START HEADER--><h1>Alexander <span class="bold">Willner</span></h1><p>Research Assistant</p></div><!--END HEADER--></header><div id="descript"><!--START DESCRIPTION--><p>Official business card of reserach assistant Alexander Willner.</p><aside id="banner"><!--START BANNER--><img src="images/update.png" alt="Last update:13.06.2010." title="Last update:13.06.2010." width="48" height="143" /></aside><!--END BANNER--></div><!--END DESCRIPTION--><article><div class="categories"><!--START CATEGORIES--><section><!--START WORK--><div id="work"><img src="images/logo_unibonn.png" height="32" width="32" alt="University of Bonn" /><div class="work"><h2 class="big">Current <span class="bold">employer</span></h2><p class="small"><a rel="me" href="http://net.cs.uni-bonn.de/willner"><em>University of Bonn</em></a></p></div></div></section><!--END WORK--><section><!--START INFO--><div id="resume" title="Press 'a'"><h2 class="slide-2">About <span class="bold">this page</span></h2></div><div id="about-list" class="section about-list"><!--START INFO LIST--><p class="paragraph">Technically speaking this small page just provides some basic information about me based on the following concepts:</p><ul class="paragraph"><li>Foundation:<a href="http://en.wikipedia.org/wiki/HTML5" title="W3C HTML5 Markup">HTML5</a> | <a href="http://en.wikipedia.org/wiki/Cascading_Style_Sheets" title="W3C CSS3 Layout">CSS3</a> | <a href="http://en.wikipedia.org/wiki/Web_Content_Accessibility_Guidelines" title="W3C Content Accessibility Guidelines">WCAG2</a> | <a href="http://en.wikipedia.org/wiki/JavaScript" title="JavaScript Scripting Language">JS</a></li><li>Semantics:<a href="http://en.wikipedia.org/wiki/RDFa" title="W3C Resource in attribute Description">RDFa</a> | <a href="http://en.wikipedia.org/wiki/GMPG" title="XHTML Friends Network">XFN</a> | <a href="http://en.wikipedia.org/wiki/FOAF_%28software%29" title="Friend of a Friend Ontology">FOAF</a> | <a href="http://en.wikipedia.org/wiki/HCard" title="Microformat Contact Details">hCard</a> | <a href="http://en.wikipedia.org/wiki/OpenID" title="Decentralized User Authenticating">OpenID</a></li><li>Data:<a href="http://en.wikipedia.org/wiki/VCard" title="Electronic Business Card">vCard</a> | <a href="http://en.wikipedia.org/wiki/Keyhole_Markup_Language" title="Google Earth Keyhole Markup Language">KML</a> | <a href="http://en.wikipedia.org/wiki/QR_Code" title="Quick Response Matrix Code">QR Code</a></li></ul><p class="paragraph">The quality of this page is assured by using the following tools:</p><ul><li>Validity:<a href="http://validator.w3.org/check?uri=http%3A%2F%2Falex.willner.ws">HTML</a> | <a href="http://jigsaw.w3.org/css-validator/validator?uri=http%3A%2F%2Fvalidato­r.w3.org%2Fcheck%3Furi%3Dhttp%253A%252F%252Falex.w­illner.ws%252F&amp;profile=css3&amp;usermedium=all&amp;warning=0">CSS</a> | <a href="http://validator.w3.org/checklink?uri=http%3A%2F%2Falex.wil­lner.ws&amp;summary=on&amp;hide_redirects=on&amp;h­ide_type=all&amp;depth=&amp;check=Check">Links</a> | <a href="http://waxler.w3.org/mobileok/check?docAddr=http%3A%2F%2Falex­.willner.ws&amp;async=true">Mobility</a> | <a href="http://wave.webaim.org/report?url=http%3A%2F%2Falex.wil­lner.ws&amp;js=2">Accessibility</a> | <a href="http://www.totalvalidator.com/validator/Revalidate?revalidate=true&amp;wai=A­AA2&amp;checklinks=false">WCAG</a> | <a href="http://tool.motoricerca.info/robots-checker.phtml?checkreferer=1">Robots</a> | <a href="http://www.validome.org/google/validate?url=http://alex.willner.ws&amp;lang=­en&amp;googleTyp=SITEMAP">Sitemap</a></li><li>Semantics:<a href="http://en.hcard.geekhood.net/?url=http%3A%2F%2Falex.wil­lner.ws#result">Microformats</a> | <a href="http://www.w3.org/2005/08/online_xslt/xslt?xmlfile=http%3A%2F%2Fwww.­w3.org%2Fservices%2Ftidy%3FpassThroughXHTML%3D1%26­docAddr%3Dhttp%253A%252F%252Falex.willner.ws&amp;x­slfile=http%3A%2F%2Fwww.w3.org%2F2002%2F08%2Fextract-semantic.xsl">W3C</a> | <a href="http://www.google.com/webmasters/tools/richsnippets?url=http://alex.willner.ws&amp;view=cse">RDF</a></li><li>Performance:<a href="http://code.google.com/speed/page-speed/">Page Speed</a> | <a href="http://developer.yahoo.com/yslow/">YSlow</a> | <a href="http://www.sitealert.de/english/">SiteAlert</a></li><li>Miscellaneous:<a href="http://browsershots.org/http://alex.willner.ws/">Browsershots</a> | <a href="http://www.seitwert.de/?url=alex.willner.ws">Seitwert</a></li></ul></div><!--END INFO LIST--></section><!--END INFO --><section><!--START CONTACT--><div class="vcard" id="hcard-Alexander-Willner" itemscope="itemscope" itemtype="http://www.data-vocabulary.org/Person"><div id="contact" title="Press 'c'"><h2 class="slide-3">Contact <span class="bold">me</span></h2></div><div id="contact-list" class="section contact-list"><!--START CONTACT LIST--><div id="contact-left"><a href="http://chart.apis.google.com/chart?chs=256x256&cht=qr&choe=UTF-8&chl=MECARD:N:Alexander%­20Willner;ADR:Bornheimer%20Str.%2039%2C%2053111%20­Bonn%2C%20Germany;TEL:%2B491784580614;EMAIL:alex@willner.ws;URL:http://alex.willner.ws;BDAY:1980­0930;NICKNAME:Alex;;"><img class="photo" itemprop="photo" src="http://chart.apis.google.com/chart?chs=64x64&cht=qr&choe=UTF-8&chl=MECARD:N:Alexander%­20Willner;ADR:Bornheimer%20Str.%2039%2C%2053111%20­Bonn%2C%20Germany;TEL:%2B491784580614;EMAIL:alex@willner.ws;URL:http://alex.willner.ws;BDAY:19800930;NICKNAME:Alex;;" alt="vCard QR Code" title="vCard QR Code" height="64" width="64" /></a><div>(<a href="http://microform.at/?type=hcard&amp;url=http%3­A%2F%2Falex.willner.ws%2F" title="Download vCard">vcf</a> | <a href="http://microform.at/?type=geo&amp;url=http%3A%2F%2Falex.willner.ws%2F" title="Download Google Earth file">kml</a>)</div></div><div id="contact-right"><div id="name" class="n"><span class="fn" itemprop="name"><span class="given-name">Alexander</span> <span class="family-name bold">Willner</span></span> (<span itemprop="nickname" class="nickname">Alex</span>),<span><span class="honorific-suffix">M. Sc.</span></span></div><p class="tel"><span class="type">Cell</span>:<a href="tel:+491784580614"><span itemprop="cell" class="value">+491784580614</span></a></p><p class="tel"><span class="type">Fax</span>:<a href="fax:+4922892985593"><span itemprop="fax" class="value">+4922892985593</span></a></p><p>Mail:<a class="email" href="mailto:alex&#064;wi­llner.ws">alex&#064;willner.ws</a> (<a href="files/alexander-willner.asc" title="Download PGP key">gpg</a> | <a href="files/alexander-willner.cer" title="Download X.509 key">x509</a>)</p><p>Chat:<a href="xmpp:alex&#064;will­ner.ws">alex&#064;willner.ws (xmpp)</a></p><p>OpenID:<a href="http://alex.willner.ws">alex.willner.ws</a></p><p>Web:<a itemprop="url" class="url" rel="me" href="http://alex.willner.ws">alex.willner.ws</a></p><div>Address:<div itemprop="address" itemscope="itemscope" itemtype="http://data-vocabulary.org/Address" class="adr"><div itemprop="treet-address" class="street-address">Bornheimer Str. 39</div><div><span itemprop="postal-code" class="postal-code">53111</span> <span itemprop="locality" class="locality">Bonn</span>,<span class="country-name">Germany</span></div><div><a href="http://maps.google.com/maps?q=Bornheimer+Str.+39,+531­11+Bonn,+Deutschland&amp;amp;sll=50.73701,7.08726" class="geo" title="50.73701;7.08726"><span class="latitude">50.73701</span>;<span class="longitude">7.08726</span></a></div></div></div></div></div><!--END CONTACT LIST--></div></section><!--END CONTACT--></div><!--END CATEGORIES--></article><footer><!--START FOOTER--><div class="footer"><p>© 2010 Alexander Willner. Inspired by this <a href="http://www.ryanglover.net/">fellow</a>.</p></div></footer></div><!--END CONTAINER--><!--GOOGLE ANALYTICS--><script type="text/javascript" src="js/willner.js"></script></body><!--END BODY--></html><!--END SITE-->

Parsed source

<html xmlns="http://www.w3.org/1999/xhtml" lang="en">
  <head>
    <meta charset="utf-8"/>
    <meta name="viewport" content="width=800"/>
    <meta name="robots" content="index,follow,noarchive"/>
    <meta name="author" content="Alexander Willner"/>
    <meta name="description" content="Official business card of reserach assistant Alexander Willner."/>
    <meta name="keywords" content="alexander,alex,willner,alexander willner,xhtml,css,standards,hcard,w3c,html5"/>
    <title>Alexander Willner | Business Card</title>
    <link rel="me" href="http://alex.willner.ws/"/>
    <link rel="openid.server" href="http://www.myopenid.com/server"/>
    <link rel="openid.delegate" href="http://id.willner.ws/alex"/>
    <link rel="openid2.local_id" href="http://id.willner.ws/alex"/>
    <link rel="openid2.provider" href="http://www.myopenid.com/server"/>
    <link rel="profile" href="http://microformats.org/profile/hcard"/>
    <link rel="profile" href="http://gmpg.org/xfn/11"/>
    <link rel="stylesheet" type="text/css" href="css/master.css"/>
    <link rel="shortcut icon" href="favicon.ico"/>
    <link rel="icon" href="favicon.ico"/>
    <link rel="meta" type="application/rdf+xml" title="vCARD" href="http://microform.at/?type=hcard-rdf&amp;url=http%3A%2F%2Falex.willner.ws"/>
    <link rel="meta" type="application/rdf+xml" title="FOAF" href="http://microform.at/?type=hfoaf&amp;url=http%3A%2F%2Falex.willner.ws"/>
    <meta http-equiv="Content-Type" content="text/html;charset=UTF-8"/>
    <!-- meta inserted by hCard Validator -->
  </head>
  <body>
    <!--START BODY-->
    <address class="email skip">Author:<a href="mailto:alex@willner.ws">Alexander Willner</a></address>
    <div id="container">
      <!--START CONTAINER-->
      <header>
        <div class="header">
          <!--START HEADER-->
          <h1>Alexander <span class="bold">Willner</span></h1>
          <p>Research Assistant</p>
        </div>
        <!--END HEADER-->
      </header>
      <div id="descript">
        <!--START DESCRIPTION-->
        <p>Official business card of reserach assistant Alexander Willner.</p>
        <aside id="banner">
          <!--START BANNER-->
          <img src="images/update.png" alt="Last update:13.06.2010." title="Last update:13.06.2010." width="48" height="143"/>
        </aside>
        <!--END BANNER-->
      </div>
      <!--END DESCRIPTION-->
      <article>
        <div class="categories">
          <!--START CATEGORIES-->
          <section>
            <!--START WORK-->
            <div id="work">
              <img src="images/logo_unibonn.png" height="32" width="32" alt="University of Bonn"/>
              <div class="work">
                <h2 class="big">Current <span class="bold">employer</span></h2>
                <p class="small">
                  <a rel="me" href="http://net.cs.uni-bonn.de/willner">
                    <em>University of Bonn</em>
                  </a>
                </p>
              </div>
            </div>
          </section>
          <!--END WORK-->
          <section>
            <!--START INFO-->
            <div id="resume" title="Press 'a'">
              <h2 class="slide-2">About <span class="bold">this page</span></h2>
            </div>
            <div id="about-list" class="section about-list">
              <!--START INFO LIST-->
              <p class="paragraph">Technically speaking this small page just provides some basic information about me based on the following concepts:</p>
              <ul class="paragraph">
                <li>Foundation:<a href="http://en.wikipedia.org/wiki/HTML5" title="W3C HTML5 Markup">HTML5</a> | <a href="http://en.wikipedia.org/wiki/Cascading_Style_Sheets" title="W3C CSS3 Layout">CSS3</a> | <a href="http://en.wikipedia.org/wiki/Web_Content_Accessibility_Guidelines" title="W3C Content Accessibility Guidelines">WCAG2</a> | <a href="http://en.wikipedia.org/wiki/JavaScript" title="JavaScript Scripting Language">JS</a></li>
                <li>Semantics:<a href="http://en.wikipedia.org/wiki/RDFa" title="W3C Resource in attribute Description">RDFa</a> | <a href="http://en.wikipedia.org/wiki/GMPG" title="XHTML Friends Network">XFN</a> | <a href="http://en.wikipedia.org/wiki/FOAF_%28software%29" title="Friend of a Friend Ontology">FOAF</a> | <a href="http://en.wikipedia.org/wiki/HCard" title="Microformat Contact Details">hCard</a> | <a href="http://en.wikipedia.org/wiki/OpenID" title="Decentralized User Authenticating">OpenID</a></li>
                <li>Data:<a href="http://en.wikipedia.org/wiki/VCard" title="Electronic Business Card">vCard</a> | <a href="http://en.wikipedia.org/wiki/Keyhole_Markup_Language" title="Google Earth Keyhole Markup Language">KML</a> | <a href="http://en.wikipedia.org/wiki/QR_Code" title="Quick Response Matrix Code">QR Code</a></li>
              </ul>
              <p class="paragraph">The quality of this page is assured by using the following tools:</p>
              <ul>
                <li>Validity:<a href="http://validator.w3.org/check?uri=http%3A%2F%2Falex.willner.ws">HTML</a> | <a href="http://jigsaw.w3.org/css-validator/validator?uri=http%3A%2F%2Fvalidato­r.w3.org%2Fcheck%3Furi%3Dhttp%253A%252F%252Falex.w­illner.ws%252F&amp;profile=css3&amp;usermedium=all&amp;warning=0">CSS</a> | <a href="http://validator.w3.org/checklink?uri=http%3A%2F%2Falex.wil­lner.ws&amp;summary=on&amp;hide_redirects=on&amp;h­ide_type=all&amp;depth=&amp;check=Check">Links</a> | <a href="http://waxler.w3.org/mobileok/check?docAddr=http%3A%2F%2Falex­.willner.ws&amp;async=true">Mobility</a> | <a href="http://wave.webaim.org/report?url=http%3A%2F%2Falex.wil­lner.ws&amp;js=2">Accessibility</a> | <a href="http://www.totalvalidator.com/validator/Revalidate?revalidate=true&amp;wai=A­AA2&amp;checklinks=false">WCAG</a> | <a href="http://tool.motoricerca.info/robots-checker.phtml?checkreferer=1">Robots</a> | <a href="http://www.validome.org/google/validate?url=http://alex.willner.ws&amp;lang=­en&amp;googleTyp=SITEMAP">Sitemap</a></li>
                <li>Semantics:<a href="http://en.hcard.geekhood.net/?url=http%3A%2F%2Falex.wil­lner.ws#result">Microformats</a> | <a href="http://www.w3.org/2005/08/online_xslt/xslt?xmlfile=http%3A%2F%2Fwww.­w3.org%2Fservices%2Ftidy%3FpassThroughXHTML%3D1%26­docAddr%3Dhttp%253A%252F%252Falex.willner.ws&amp;x­slfile=http%3A%2F%2Fwww.w3.org%2F2002%2F08%2Fextract-semantic.xsl">W3C</a> | <a href="http://www.google.com/webmasters/tools/richsnippets?url=http://alex.willner.ws&amp;view=cse">RDF</a></li>
                <li>Performance:<a href="http://code.google.com/speed/page-speed/">Page Speed</a> | <a href="http://developer.yahoo.com/yslow/">YSlow</a> | <a href="http://www.sitealert.de/english/">SiteAlert</a></li>
                <li>Miscellaneous:<a href="http://browsershots.org/http://alex.willner.ws/">Browsershots</a> | <a href="http://www.seitwert.de/?url=alex.willner.ws">Seitwert</a></li>
              </ul>
            </div>
            <!--END INFO LIST-->
          </section>
          <!--END INFO -->
          <section>
            <!--START CONTACT-->
            <div class="vcard" id="hcard-Alexander-Willner" itemscope="itemscope" itemtype="http://www.data-vocabulary.org/Person">
              <div id="contact" title="Press 'c'">
                <h2 class="slide-3">Contact <span class="bold">me</span></h2>
              </div>
              <div id="contact-list" class="section contact-list">
                <!--START CONTACT LIST-->
                <div id="contact-left">
                  <a href="http://chart.apis.google.com/chart?chs=256x256&amp;cht=qr&amp;choe=UTF-8&amp;chl=MECARD:N:Alexan­der%20Willner;ADR:Bornheimer%20Str.%2039%2C%205311­1%20Bonn%2C%20Germany;TEL:%2B491784580614;EMAIL:alex@willner.ws;URL:http://alex.willner.ws;BDAY:19800930;NICKNAME:Alex;;">
                    <img class="photo" itemprop="photo" src="http://chart.apis.google.com/chart?chs=64x64&amp;cht=qr&amp;choe=UTF-8&amp;chl=MECARD:N:Alexan­der%20Willner;ADR:Bornheimer%20Str.%2039%2C%205311­1%20Bonn%2C%20Germany;TEL:%2B491784580614;EMAIL:alex@willner.ws;URL:http://alex.willner.ws;BDAY:19800930;NICKNAME:Alex;;" alt="vCard QR Code" title="vCard QR Code" height="64" width="64"/>
                  </a>
                  <div>(<a href="http://microform.at/?type=hcard&amp;url=http%3­A%2F%2Falex.willner.ws%2F" title="Download vCard">vcf</a> | <a href="http://microform.at/?type=geo&amp;url=http%3A%2F%2Falex.willner.ws%2F" title="Download Google Earth file">kml</a>)</div>
                </div>
                <div id="contact-right">
                  <div id="name" class="n"><span class="fn" itemprop="name"><span class="given-name">Alexander</span> <span class="family-name bold">Willner</span></span> (<span itemprop="nickname" class="nickname">Alex</span>),<span><span class="honorific-suffix">M. Sc.</span></span></div>
                  <p class="tel"><span class="type">Cell</span>:<a href="tel:+491784580614"><span itemprop="cell" class="value">+491784580614</span></a></p>
                  <p class="tel"><span class="type">Fax</span>:<a href="fax:+4922892985593"><span itemprop="fax" class="value">+4922892985593</span></a></p>
                  <p>Mail:<a class="email" href="mailto:alex@willner.ws">alex@willner.ws</a> (<a href="files/alexander-willner.asc" title="Download PGP key">gpg</a> | <a href="files/alexander-willner.cer" title="Download X.509 key">x509</a>)</p>
                  <p>Chat:<a href="xmpp:alex@willner.ws">alex@willner.ws (xmpp)</a></p>
                  <p>OpenID:<a href="http://alex.willner.ws">alex.willner.ws</a></p>
                  <p>Web:<a itemprop="url" class="url" rel="me" href="http://alex.willner.ws">alex.willner.ws</a></p>
                  <div>Address:<div itemprop="address" itemscope="itemscope" itemtype="http://data-vocabulary.org/Address" class="adr"><div itemprop="treet-address" class="street-address">Bornheimer Str. 39</div><div><span itemprop="postal-code" class="postal-code">53111</span> <span itemprop="locality" class="locality">Bonn</span>,<span class="country-name">Germany</span></div><div><a href="http://maps.google.com/maps?q=Bornheimer+Str.+39,+531­11+Bonn,+Deutschland&amp;amp;sll=50.73701,7.08726" class="geo" title="50.73701;7.08726"><span class="latitude">50.73701</span>;<span class="longitude">7.08726</span></a></div></div></div>
                </div>
              </div>
              <!--END CONTACT LIST-->
            </div>
          </section>
          <!--END CONTACT-->
        </div>
        <!--END CATEGORIES-->
      </article>
      <footer>
        <!--START FOOTER-->
        <div class="footer">
          <p>© 2010 Alexander Willner. Inspired by this <a href="http://www.ryanglover.net/">fellow</a>.</p>
        </div>
      </footer>
    </div>
    <!--END CONTAINER-->
    <!--GOOGLE ANALYTICS-->
    <script type="text/javascript" src="js/willner.js"/>
  </body>
  <!--END BODY-->
</html>

Credits

Written by . Icons are from Tango Icon Library. Test cases include hCard Acid test by Dmitry Baranovskiy, examples from microformats.org and hCard test suite.

Source code is available under the BSD license.

¹ It's not a validator in the XML/SGML sense.