RDF or XML?

• Q: For a specific application, should I use XML or RDF?
• A: It depends...
  • XML's model is
    • a tree, ie, a strong hierarchy
    • applications may rely on hierarchy position (eg, li in HTML)
    • relatively simple syntax and structure
    • not easy to combine trees
  • RDF's model is
    • a loose collections of relations
    • applications may do "database"-like search
    • not easy to recover hierarchy
    • easy to combine relations in one big collection