Started but not completed:
  - XPath: a sample and currently incomplete implementation
Todo:
  - XPointer: built on top of XPath allow to address any portion of an XML
    document
- XLink detection: detect XML hypertext links and implement a simple link
    database
- Schemas:  new version obsoleting DTDs inherited from SGML
Add-ons worked on:
  - Gdome: the DOM interface
- Gtkhtml2: new version of the Gnome HTML widget