GTT-Technologies

GTT-Technologies is a privately held German company based in Herzogenrath, near Aachen, that specializes in technical thermochemistry. Founded in 1983, it was among the pioneers in applying thermochemistry to industrial problem-solving. The company provides software, thermochemical data, and consulting services that help metallurgists, materials scientists, and process engineers navigate "chemical space" — the multidimensional domain of chemical reactions and phase equilibria. GTT-Technologies is best known for the ChemSage family of software programs, which includes FactSage, a Windows-based integrated thermodynamic database system; ChemApp, a programmer's toolkit; and ChemSheet, a spreadsheet tool for complex equilibria. These tools are used in industries such as steelmaking, copper metallurgy, energy conversion, materials design, and materials informatics. The company also offers training courses, including a FactSage online course and a Calphad Optimizer course. GTT-Technologies operates globally, working closely with partners at ThermFact and maintaining a network of dedicated sales representatives. Its roots trace back to the Lehrstuhl für Werkstoffchemie (Materials Chemistry) at RWTH Aachen University, and its software builds on the lifelong development activities of Gunnar Eriksson. The company continues to evolve its products, recently highlighting applications such as copper smelting flowsheets and agentic coding, and hosts user meetings to share scientific developments.

GTT-Technologies was founded in 1983 and has specialized in the field of Technical Thermochemistry since then. The company was among the pioneers in the practical application of thermochemistry to analyze industrial problems. Its roots lie at the Lehrstuhl für Werkstoffchemie (Materials Chemistry) of RWTH Aachen University. Over the years, GTT-Technologies has constantly improved its capabilities and now offers a wide range of products and services in technical thermochemistry. The renowned ChemSage family of software programs includes FactSage, ChemApp, and ChemSheet, based on the lifelong development activities of Gunnar Eriksson. The company is located in Herzogenrath near Aachen, Germany, and operates globally, working closely with partners at ThermFact and maintaining a strong network of dedicated sales representatives. GTT-Technologies continues to evolve its products, adding new software and services, and hosts user meetings to share scientific and technical developments.

• 2026

  Users' Meeting 2026 held; presentation recordings made available online.

• 1983

  GTT-Technologies founded, specializing in Technical Thermochemistry.

• Development of the ChemSage family of software programs, including FactSage, ChemApp, and ChemSheet.

Specialist in technical thermochemistry, providing tools for navigation in chemical space.

• FactSage

  Windows-based integrated thermodynamic database system.

• ChemApp

  Programmer's toolkit for thermochemical calculations.

• ChemSheet

  Spreadsheet tool for easy use of complex equilibria.

• ChemSage

  Family of software programs for thermochemical modeling.

1. 1Thermochemical Simulation Software | GTT-Technologiesgtt-technologies.de
2. 2About us - GTT-Technologiesgtt-technologies.de
3. 3GTT - The Single Source for Thermochemistry Tools - GTT-Technologiesgtt-technologies.de
4. 4Contact us - GTT-Technologiesgtt-technologies.de
5. 5GTT-Technologies (Germany) - Wikidatawikidata.org