What is WG1 developing and maintaining?

RELAX NG (ISO/IEC 19757-2)

Schematron (ISO/IEC 19757-3)

NVDL – Namespace-based Validation Dispatching Language (ISO/IEC 19757-4)

Extensible Datatypes (still in draft)

CREPDL – Character Repertoire Description Language (ISO/IEC 19757-7)

DSRL – Document Semantics Renaming Language (ISO/IEC 19757-8)

Namespace and datatype declaration in Document Type Definitions (ISO/IEC 19757-9)

Schema Association aka xml-model (soon too be ISO/IEC 19757-11)