STEP is an international standard (ISO 10303) for the representation and modelling of information used over the lifecycle of manufactured products.

Part 21 of STEP is a standard for the exchange of product information in a text file format.

This website presents tools for developing applications which access and use the information in a STEP Part 21 file. Some features of this toolset are:

• Use of open-source and platform-independent software
• A scripting style of development, in which applications are constructed from combining the actions of several executable programs using a general purpose interpreted scripting language

This approach is complementary to the use of monolithic applications such as CAD/CAM/PDM packages to generate and read STEP files.

• Create web-ready views of STEP data
• Merge CAD geometry with product data
• Extract information for other application environments

• An application which translates the information content of a Part 21 file into a file of ground Prolog clauses.
• The SWI-Prolog interpreter.
  • Prolog language scripts which analyse the Prolog clause sets generated by the interpreter and produce useful output
• Python interpreter and Python language modules and scripts for:
  • Text parsing of EXPRESS schema and Part 21 files
  • Writing Part 21 files
  • Coordinating execution of translation and Prolog processing
  • Implementing cgi (Common Gateway Interface) scripts for web based applications

• Translation of Part 21 sets to Prolog clauses -- documents the translation process and demonstrates online translation and generation of web views.
• read_exchange_structure -- Downloadable source code for the C++ application which reads STEP Part 21 files and produces Prolog clauses representing the data contained in the file. Source code made available under terms of the GPL (Gnu Public License)
• repackage -- Web-based demonstration of repackaging Part 21 files; will allow uploading a Part 21 file, setting additional product data using HTML forms, and downloading a new Part 21 file incorporating the product data entered by user and geometry from the uploaded file.