XML Schema documentation generator

One of the nicest advantage of using XML Schema is the automated documentation generation. First add annotations to your schema:

<xs:element name="Prout">
  <xs:annotation>
    <xs:documentation>This is a prout.</xs:documentation>
  </xs:annotation>
<xs:element>

Then use one of the following tool:

• xs3p: An XSLT script. Its main advantage is that it’s create a documentation on one page. It’s nice to generate PDF files or integrate in Office documents.
• xsddoc: It generate javadoc like documentation. Best for online documentation.

I did not found any other free as in speech tool.