From https://stackoverflow.com/a/10174257/672885

README.md

Test

Pushing to this gist via Git repo

html2docbook.xsl

<?xml version="1.0" encoding="UTF-8"?> 
<xsl:stylesheet version="1.0"  
                xmlns:xsl="http://www.w3.org/1999/XSL/Transform"  
                xmlns:fo="http://www.w3.org/1999/XSL/Format"  
                xmlns:html="http://www.w3.org/1999/xhtml"  
                xmlns:saxon="http://icl.com/saxon" 
                exclude-result-prefixes="xsl fo html saxon"> 

<xsl:output method="xml" indent="no"/> 
<xsl:param name="filename"></xsl:param>  
<xsl:param name="prefix">wb</xsl:param> 
<xsl:param name="graphics_location">file:///epicuser/AISolutions/graphics/AIWorkbench/</xsl:param> 

<!-- Main block-level conversions --> 
<xsl:template match="html:html"> 
 <xsl:apply-templates select="html:body"/> 
</xsl:template> 

<!-- This template converts each HTML file encountered into a DocBook  
     section.  For a title, it selects the first h1 element --> 
<xsl:template match="html:body"> 
 <section> 
  <xsl:if test="$filename != ''"> 
   <xsl:attribute name="id"> 
    <xsl:value-of select="$prefix"/> 
    <xsl:text>_</xsl:text> 
    <xsl:value-of select="translate($filename,' ()','__')"/> 
   </xsl:attribute> 
  </xsl:if> 
  <title> 
   <xsl:value-of select=".//html:h1[1] 
                         |.//html:h2[1] 
                         |.//html:h3[1]"/> 
  </title> 
  <xsl:apply-templates select="*"/> 
 </section> 
</xsl:template> 

<!-- This template matches on all HTML header items and makes them into  
     bridgeheads. It attempts to assign an ID to each bridgehead by looking  
     for a named anchor as a child of the header or as the immediate preceding 
     or following sibling --> 
<xsl:template match="html:h1 
              |html:h2 
              |html:h3 
              |html:h4 
              |html:h5 
              |html:h6"> 
 <bridgehead> 
  <xsl:choose> 
   <xsl:when test="count(html:a/@name)"> 
    <xsl:attribute name="id"> 
     <xsl:value-of select="html:a/@name"/> 
    </xsl:attribute> 
   </xsl:when> 
   <xsl:when test="preceding-sibling::* = preceding-sibling::html:a[@name != '']"> 
    <xsl:attribute name="id"> 
    <xsl:value-of select="concat($prefix,preceding-sibling::html:a[1]/@name)"/> 
    </xsl:attribute> 
   </xsl:when> 
   <xsl:when test="following-sibling::* = following-sibling::html:a[@name != '']"> 
    <xsl:attribute name="id"> 
    <xsl:value-of select="concat($prefix,following-sibling::html:a[1]/@name)"/> 
    </xsl:attribute> 
   </xsl:when> 
  </xsl:choose> 
  <xsl:apply-templates/> 
 </bridgehead> 
</xsl:template> 

<!-- These templates perform one-to-one conversions of HTML elements into 
     DocBook elements --> 
<xsl:template match="html:p"> 
<!-- if the paragraph has no text (perhaps only a child <img>), don't  
     make it a para --> 
 <xsl:choose> 
  <xsl:when test="normalize-space(.) = ''"> 
   <xsl:apply-templates/> 
  </xsl:when> 
  <xsl:otherwise> 
 <para> 
  <xsl:apply-templates/> 
 </para> 
  </xsl:otherwise> 
 </xsl:choose> 
</xsl:template> 
<xsl:template match="html:pre"> 
 <programlisting> 
  <xsl:apply-templates/> 
 </programlisting> 
</xsl:template> 

<!-- Hyperlinks --> 
<xsl:template match="html:a[contains(@href,'http://')]" priority="1.5"> 
 <ulink> 
  <xsl:attribute name="url"> 
   <xsl:value-of select="normalize-space(@href)"/> 
  </xsl:attribute> 
  <xsl:apply-templates/> 
 </ulink> 
</xsl:template> 

<xsl:template match="html:a[contains(@href,'#')]" priority="0.6"> 
 <xref> 
  <xsl:attribute name="linkend"> 
   <xsl:call-template name="make_id"> 
    <xsl:with-param name="string" select="substring-after(@href,'#')"/> 
   </xsl:call-template> 
  </xsl:attribute> 
 </xref> 
</xsl:template> 

<xsl:template match="html:a[@href != '']"> 
 <xref> 
  <xsl:attribute name="linkend"> 
   <xsl:value-of select="$prefix"/> 
   <xsl:text>_</xsl:text> 
   <xsl:call-template name="make_id"> 
    <xsl:with-param name="string" select="@href"/> 
   </xsl:call-template> 
  </xsl:attribute> 
 </xref> 
</xsl:template> 

<!-- Need to come up with good template for converting filenames into ID's --> 
<xsl:template name="make_id"> 
 <xsl:param name="string" select="''"/> 
 <xsl:variable name="fixedname"> 
  <xsl:call-template name="get_filename"> 
   <xsl:with-param name="path" select="translate($string,' \()','_/_')"/> 
  </xsl:call-template> 
 </xsl:variable> 
 <xsl:choose> 
  <xsl:when test="contains($fixedname,'.htm')"> 
   <xsl:value-of select="substring-before($fixedname,'.htm')"/> 
  </xsl:when> 
  <xsl:otherwise> 
   <xsl:value-of select="$fixedname"/> 
  </xsl:otherwise> 
 </xsl:choose> 
</xsl:template> 

<xsl:template name="string.subst"> 
 <xsl:param name="string" select="''"/> 
 <xsl:param name="substitute" select="''"/> 
 <xsl:param name="with" select="''"/> 
 <xsl:choose> 
  <xsl:when test="contains($string,$substitute)"> 
   <xsl:variable name="pre" select="substring-before($string,$substitute)"/> 
   <xsl:variable name="post" select="substring-after($string,$substitute)"/> 
   <xsl:call-template name="string.subst"> 
    <xsl:with-param name="string" select="concat($pre,$with,$post)"/> 
    <xsl:with-param name="substitute" select="$substitute"/> 
    <xsl:with-param name="with" select="$with"/> 
   </xsl:call-template> 
  </xsl:when> 
  <xsl:otherwise> 
   <xsl:value-of select="$string"/> 
  </xsl:otherwise> 
 </xsl:choose> 
</xsl:template> 

<!-- Images --> 
<!-- Images and image maps --> 
<xsl:template match="html:img"> 
 <xsl:variable name="tag_name"> 
  <xsl:choose> 
   <xsl:when test="boolean(parent::html:p) and  
        boolean(normalize-space(parent::html:p/text()))"> 
    <xsl:text>inlinemediaobject</xsl:text> 
   </xsl:when> 
   <xsl:otherwise>mediaobject</xsl:otherwise> 
  </xsl:choose> 
 </xsl:variable> 
 <xsl:element name="{$tag_name}"> 
  <imageobject> 
   <xsl:call-template name="process.image"/> 
  </imageobject> 
 </xsl:element> 
</xsl:template> 

<xsl:template name="process.image"> 
 <imagedata> 
<xsl:attribute name="fileref"> 
 <xsl:call-template name="make_absolute"> 
  <xsl:with-param name="filename" select="@src"/> 
 </xsl:call-template> 
</xsl:attribute> 
<xsl:if test="@height != ''"> 
 <xsl:attribute name="depth"> 
  <xsl:value-of select="@height"/> 
 </xsl:attribute> 
</xsl:if> 
<xsl:if test="@width != ''"> 
 <xsl:attribute name="width"> 
  <xsl:value-of select="@width"/> 
 </xsl:attribute> 
</xsl:if> 
 </imagedata> 
</xsl:template> 

<xsl:template name="make_absolute"> 
 <xsl:param name="filename"/> 
 <xsl:variable name="name_only"> 
  <xsl:call-template name="get_filename"> 
   <xsl:with-param name="path" select="$filename"/> 
  </xsl:call-template> 
 </xsl:variable> 
 <xsl:value-of select="$graphics_location"/><xsl:value-of select="$name_only"/> 
</xsl:template> 

<xsl:template match="html:ul[count(*) = 0]"> 
 <xsl:message>Matched</xsl:message> 
 <blockquote> 
  <xsl:apply-templates/> 
 </blockquote> 
</xsl:template> 

<xsl:template name="get_filename"> 
 <xsl:param name="path"/> 
 <xsl:choose> 
  <xsl:when test="contains($path,'/')"> 
   <xsl:call-template name="get_filename"> 
    <xsl:with-param name="path" select="substring-after($path,'/')"/> 
   </xsl:call-template> 
  </xsl:when> 
  <xsl:otherwise> 
   <xsl:value-of select="$path"/> 
  </xsl:otherwise> 
 </xsl:choose> 
</xsl:template> 

<!-- LIST ELEMENTS --> 
<xsl:template match="html:ul"> 
 <itemizedlist> 
  <xsl:apply-templates/> 
 </itemizedlist> 
</xsl:template> 

<xsl:template match="html:ol"> 
 <orderedlist> 
  <xsl:apply-templates/> 
 </orderedlist> 
</xsl:template> 

<!-- This template makes a DocBook variablelist out of an HTML definition list --> 
<xsl:template match="html:dl"> 
 <variablelist> 
  <xsl:for-each select="html:dt"> 
   <varlistentry> 
    <term> 
     <xsl:apply-templates/> 
    </term> 
    <listitem> 
     <xsl:apply-templates select="following-sibling::html:dd[1]"/> 
    </listitem> 
   </varlistentry> 
  </xsl:for-each> 
 </variablelist> 
</xsl:template> 

<xsl:template match="html:dd"> 
 <xsl:choose> 
  <xsl:when test="boolean(html:p)"> 
   <xsl:apply-templates/> 
  </xsl:when> 
  <xsl:otherwise> 
   <para> 
    <xsl:apply-templates/> 
   </para> 
  </xsl:otherwise> 
 </xsl:choose> 
</xsl:template> 

<xsl:template match="html:li"> 
 <listitem> 
  <xsl:choose> 
   <xsl:when test="count(html:p) = 0"> 
    <para> 
     <xsl:apply-templates/> 
    </para> 
   </xsl:when> 
   <xsl:otherwise> 
    <xsl:apply-templates/> 
   </xsl:otherwise> 
  </xsl:choose> 
 </listitem> 
</xsl:template> 

<xsl:template match="*"> 
 <xsl:message>No template for <xsl:value-of select="name()"/> 
 </xsl:message> 
 <xsl:apply-templates/> 
</xsl:template> 

<xsl:template match="@*"> 
 <xsl:message>No template for <xsl:value-of select="name()"/> 
 </xsl:message> 
 <xsl:apply-templates/> 
</xsl:template> 

<!-- inline formatting --> 
<xsl:template match="html:b"> 
 <emphasis role="bold"> 
  <xsl:apply-templates/> 
 </emphasis> 
</xsl:template> 
<xsl:template match="html:i"> 
 <emphasis> 
  <xsl:apply-templates/> 
 </emphasis> 
</xsl:template> 
<xsl:template match="html:u"> 
 <citetitle> 
  <xsl:apply-templates/> 
 </citetitle> 
</xsl:template> 

<!-- Ignored elements --> 
<xsl:template match="html:hr"/> 
<xsl:template match="html:h1[1]|html:h2[1]|html:h3[1]" priority="1"/> 
<xsl:template match="html:br"/> 
<xsl:template match="html:p[normalize-space(.) = '' and count(*) = 0]"/> 
<xsl:template match="text()"> 
 <xsl:choose> 
  <xsl:when test="normalize-space(.) = ''"></xsl:when> 
  <xsl:otherwise><xsl:copy/></xsl:otherwise> 
 </xsl:choose> 
</xsl:template> 

<!-- Workbench Hacks --> 
<xsl:template match="html:div[contains(@style,'margin-left: 2em')]"> 
 <blockquote><para> 
  <xsl:apply-templates/></para> 
 </blockquote> 
</xsl:template> 

<xsl:template match="html:a[@href != ''  
                      and not(boolean(ancestor::html:p|ancestor::html:li))]"  
              priority="1"> 
 <para> 
 <xref> 
  <xsl:attribute name="linkend"> 
   <xsl:value-of select="$prefix"/> 
   <xsl:text>_</xsl:text> 
   <xsl:call-template name="make_id"> 
    <xsl:with-param name="string" select="@href"/> 
   </xsl:call-template> 
  </xsl:attribute> 
 </xref> 
 </para> 
</xsl:template> 

<xsl:template match="html:a[contains(@href,'#')  
                    and not(boolean(ancestor::html:p|ancestor::html:li))]"  
              priority="1.1"> 
 <para> 
 <xref> 
  <xsl:attribute name="linkend"> 
   <xsl:value-of select="$prefix"/> 
   <xsl:text>_</xsl:text> 
   <xsl:call-template name="make_id"> 
    <xsl:with-param name="string" select="substring-after(@href,'#')"/> 
   </xsl:call-template> 
  </xsl:attribute> 
 </xref> 
 </para> 
</xsl:template> 

<!-- Table conversion --> 
<xsl:template match="html:table"> 
<!-- <xsl:variable name="column_count" 
               select="saxon:max(.//html:tr,saxon:expression('count(html:td)'))"/> --> 
 <xsl:variable name="column_count"> 
  <xsl:call-template name="count_columns"> 
   <xsl:with-param name="table" select="."/> 
  </xsl:call-template> 
 </xsl:variable> 
 <informaltable> 
  <tgroup> 
   <xsl:attribute name="cols"> 
    <xsl:value-of select="$column_count"/> 
   </xsl:attribute> 
   <xsl:call-template name="generate-colspecs"> 
    <xsl:with-param name="count" select="$column_count"/> 
   </xsl:call-template> 
   <thead> 
    <xsl:apply-templates select="html:tr[1]"/> 
   </thead> 
   <tbody> 
    <xsl:apply-templates select="html:tr[position() != 1]"/> 
   </tbody> 
  </tgroup> 
 </informaltable> 
</xsl:template> 

<xsl:template name="generate-colspecs"> 
 <xsl:param name="count" select="0"/> 
 <xsl:param name="number" select="1"/> 
 <xsl:choose> 
  <xsl:when test="$count &lt; $number"/> 
  <xsl:otherwise> 
   <colspec> 
    <xsl:attribute name="colnum"> 
     <xsl:value-of select="$number"/> 
    </xsl:attribute> 
    <xsl:attribute name="colname"> 
     <xsl:value-of select="concat('col',$number)"/> 
    </xsl:attribute> 
   </colspec> 
   <xsl:call-template name="generate-colspecs"> 
    <xsl:with-param name="count" select="$count"/> 
    <xsl:with-param name="number" select="$number + 1"/> 
   </xsl:call-template> 
  </xsl:otherwise> 
 </xsl:choose> 
</xsl:template> 

<xsl:template match="html:tr"> 
 <row> 
  <xsl:apply-templates/> 
 </row> 
</xsl:template> 

<xsl:template match="html:th|html:td"> 
 <xsl:variable name="position" select="count(preceding-sibling::*) + 1"/> 
 <entry> 
  <xsl:if test="@colspan &gt; 1"> 
   <xsl:attribute name="namest"> 
    <xsl:value-of select="concat('col',$position)"/> 
   </xsl:attribute> 
   <xsl:attribute name="nameend"> 
    <xsl:value-of select="concat('col',$position + number(@colspan) - 1)"/> 
   </xsl:attribute> 
  </xsl:if> 
  <xsl:if test="@rowspan &gt; 1"> 
   <xsl:attribute name="morerows"> 
    <xsl:value-of select="number(@rowspan) - 1"/> 
   </xsl:attribute> 
  </xsl:if> 
  <xsl:apply-templates/> 
 </entry> 
</xsl:template> 

<xsl:template match="html:td_null"> 
 <xsl:apply-templates/> 
</xsl:template> 

<xsl:template name="count_columns"> 
 <xsl:param name="table" select="."/> 
 <xsl:param name="row" select="$table/html:tr[1]"/> 
 <xsl:param name="max" select="0"/> 
 <xsl:choose>  
  <xsl:when test="local-name($table) != 'table'"> 
   <xsl:message>Attempting to count columns on a non-table element</xsl:message> 
  </xsl:when> 
  <xsl:when test="local-name($row) != 'tr'"> 
   <xsl:message>Row parameter is not a valid row</xsl:message> 
  </xsl:when> 
  <xsl:otherwise> 
   <!-- Count cells in the current row --> 
   <xsl:variable name="current_count"> 
    <xsl:call-template name="count_cells"> 
     <xsl:with-param name="cell" select="$row/html:td[1]|$row/html:th[1]"/> 
    </xsl:call-template> 
   </xsl:variable> 
   <!-- Check for the maximum value of $current_count and $max --> 
   <xsl:variable name="new_max"> 
    <xsl:choose> 
     <xsl:when test="$current_count &gt; $max"> 
      <xsl:value-of select="number($current_count)"/> 
     </xsl:when> 
     <xsl:otherwise> 
      <xsl:value-of select="number($max)"/> 
     </xsl:otherwise> 
    </xsl:choose> 
   </xsl:variable> 
   <!-- If this is the last row, return $max, otherwise continue --> 
   <xsl:choose> 
    <xsl:when test="count($row/following-sibling::html:tr) = 0"> 
     <xsl:value-of select="$new_max"/> 
    </xsl:when> 
    <xsl:otherwise> 
     <xsl:call-template name="count_columns"> 
      <xsl:with-param name="table" select="$table"/> 
      <xsl:with-param name="row" select="$row/following-sibling::html:tr"/> 
      <xsl:with-param name="max" select="$new_max"/> 
     </xsl:call-template> 
    </xsl:otherwise> 
   </xsl:choose> 
  </xsl:otherwise> 
 </xsl:choose> 
</xsl:template> 

<xsl:template name="count_cells"> 
 <xsl:param name="cell"/> 
 <xsl:param name="count" select="0"/> 
 <xsl:variable name="new_count"> 
  <xsl:choose> 
   <xsl:when test="$cell/@colspan &gt; 1"> 
    <xsl:value-of select="number($cell/@colspan) + number($count)"/> 
   </xsl:when> 
   <xsl:otherwise> 
    <xsl:value-of select="number('1') + number($count)"/> 
   </xsl:otherwise> 
  </xsl:choose> 
 </xsl:variable> 
 <xsl:choose> 
  <xsl:when test="count($cell/following-sibling::*) &gt; 0"> 
   <xsl:call-template name="count_cells"> 
    <xsl:with-param name="cell" 
                    select="$cell/following-sibling::*[1]"/> 
    <xsl:with-param name="count" select="$new_count"/> 
   </xsl:call-template> 
  </xsl:when> 
  <xsl:otherwise> 
   <xsl:value-of select="$new_count"/> 
  </xsl:otherwise> 
 </xsl:choose> 
</xsl:template> 

</xsl:stylesheet>