Distinct XSLT 1.0

distinct.xsl

<xsl:key name="product" match="/xpath/xpath/text()" use="." />

<xsl:template match="/">

  <xsl:for-each select="/xpath/xpath/text()[generate-id()= generate-id(key('product',.)[1])]">
    <li>
      <xsl:value-of select="."/>
    </li>
  </xsl:for-each>

</xsl:template>