What is the difference between XML Schema (XSD) and XDR schema?
The XML Schema definition language (XSD) is the current World Wide Web Consortium (W3C) specification for XML schemas. XML-Data Reduced (XDR) schema is an interim schema language offered to developers while the W3C worked on a draft implementation. MSXML versions 4.0 and 5.0 support both XML Schema (XSD) and XDR schema. MSXML version 6.0 supports only XSD Schema.