Materials Science International (MSI) is a global research and publishing company specializing in materials science, particularly materials constitution and thermodynamics. Its central product, MSI Eureka, is a knowledgebase focused on inorganic materials and related systems, including alloys, non-metals and composites. The database brings together phase diagrams, crystal structures, thermodynamic information and other evaluated constitutional data, with more than 536,000 entries covering binary, ternary and multicomponent systems.

MSI also publishes the Ternary Alloys book series, featuring critically evaluated materials data and specialist topics such as magnet systems for wind power, electric motors and sensors. Through its Materials Science International Team (MSIT), a global network of experts collaborating with MSI on phase diagram evaluation, the company delivers training and professional events. These include winter schools, workshops and seminars on materials chemistry, thermodynamics, rare-earth materials and magnet technology. MSI additionally provides engineering and scientific consultancy and contract research for industrial clients, and supports large-scale research programs worldwide. Its resources include free research tools, tutorials and sample database content.