• freely intermix tag sets of different sets of tag semantics (using XML namespaces), without disturbing each other (such as by name clash) in the global world
  • add your new tags to HTML (and other XML-based formats)
    • get rid of using HTML in future Web, switch it to proper semantic XML formats
      • make XSL-format based browsers with automatic generation of XSL from other XML formats
    • make automatic coloring of source listings (for example)
  • add macroses and include (such as by XInclude) other files in XML
  • intermix different XML formats, with intelligent automatic processing of the mix
    • embed one XML format in another one
    • automatically choose the order of different XML converters applied to your mixed XML file
  • make browsers to show your XML in arbitrary format
  • make processing XML intelligent (with your custom scripts)
  • integrating together XML conversion and validation scripts written in multiple programming languages
  • associating semantics (such as relations with other namespaces and validation rules) to a namespace
    • semantics can be described as an RDF resource at a namespace URL (or a related URL)
  • TODO
  • many more opportunities
  • integrate all of the above in single command