W3C XML Schema approach | NVDL approach |
---|---|
All possible usages of vocabulary has to be known in advance. | Vocabularies can be combined on demand. |
“Early binding” between namespaces | “Late binding” between namespaces |
“Tightly” coupled schemas | “Loosely” coupled schemas |
Driven by authors of “base” vocabularies and their schemas. | Driven by users and needs of their compound documents. |
Best practice: Create single namespace schemas for individual XML languages and move any compound language definitions to a separate layer (NVDL).