How really?

More markup.

<para>There are <phrase xlink:type="extended">
  <phrase xlink:label="source" xlink:type="resource"
          role="extended-link">several implementations</phrase>
  <link xlink:type="locator" xlink:label="target"
        xlink:href="https://github.com/docbook/xslTNG"
        xlink:title="XSLT 3.0"/>
  <link xlink:type="locator" xlink:label="target"
        xlink:href="https://github.com/docbook/xslt20-stylesheets"
        xlink:title="XSLT 2.0"/>
  <link xlink:type="locator" xlink:label="target"
        xlink:href="https://github.com/docbook/xslt10-stylesheets"
        xlink:title="XSLT 1.0"/>
  <link xlink:type="locator" xlink:label="target"
        xlink:href="https://github.com/docbook/dsssl"
        xlink:title="DSSSL"/>
  <link xlink:to="target" xlink:from="source" xlink:type="arc"/></phrase>
of stylesheets for DocBook.</para>

How really?

More markup.

<para>There are <phrase xlink:type="extended">
  <phrase xlink:label="source" xlink:type="resource"
          role="extended-link">several implementations</phrase>
  <link xlink:type="locator" xlink:label="target"
        xlink:href="https://github.com/docbook/xslTNG"
        xlink:title="XSLT 3.0"/>
  <link xlink:type="locator" xlink:label="target"
        xlink:href="https://github.com/docbook/xslt20-stylesheets"
        xlink:title="XSLT 2.0"/>
  <link xlink:type="locator" xlink:label="target"
        xlink:href="https://github.com/docbook/xslt10-stylesheets"
        xlink:title="XSLT 1.0"/>
  <link xlink:type="locator" xlink:label="target"
        xlink:href="https://github.com/docbook/dsssl"
        xlink:title="DSSSL"/>
  <link xlink:to="target" xlink:from="source" xlink:type="arc"/></phrase>
of stylesheets for DocBook.</para>

Speaker notes

It didn’t, of course. This is what’s really going on. This is what the stylesheets support.