Optimizations and performance improvements
Handling of source documents
XSLT 2.0 implementation
XQuery 1.0 implementation
JAXP interface (transformation, XPath, schema processing)
System Programming Interfaces
Changes specific to .NET
XML Schema 1.0 implementation
Functions, operators, and data types for XPath 2.0
Support for DOM and other external tree models
Using Saxon from Ant
Internal changes