List of OSS or free STEP programs

Express Schemas

SC4 Express Archive - for STEP AP schemas that are International Standards (IS)

STEPmod on Sourceforge - for versions of modular STEP AP schemas that are in development

Express Engine - used to validate models with schemas. Old website is here

Open Source BIM Collective

JSDAI, similar to STEPcode but written in Java. Created by LKSoftWare GmbH.


Express for Free, also here

SEBNF2Pars - Creates Part 21 parsers from an EBNF representation

lgtstep - a Logtalk STEP implementation

Scripting Applications for STEP Part 21 files - uses Prolog

expfront - free on-line EXPRESS schema checker

IDA-STEP Viewer - free downloadable STEP file viewer

Jen-X p28 schema generator and p21-p28 mediators - for shipbuilding STEP AP’s

OntoSTEP Protégé plugin


STEP File Analyzer