Specifications
Standards & References
ISO 10303 standards, BNF grammar references, and key publications for the EXPRESS language family.
ISO 10303 Standards
The EXPRESS language family is defined within ISO 10303 (STEP — Standard for the Exchange of Product model data).
EXPRESS Language
The core information modelling language for defining data schemas, entities, types, and constraints. Edition 2 published 2004.
EXPRESS-I
Instance definition language for populated data models and conformance test cases.
EXPRESS-X / EXPRESS-Q
Schema mapping and query languages for transforming and interrogating EXPRESS data.
STEP Physical File
Clear-text encoding of product data (Part 21 file format). The most widely deployed STEP exchange format.
STEP XML Binding
XML representation of EXPRESS-driven data for web-based exchange.
BNF Grammars
Download formal grammar definitions for each standard.
Key References
Essential publications on the EXPRESS language family.
STEP: An Introduction
Jon Owen
Information Geometers, 1993