3D XML (3D eXtensible Markup Language) is a proprietary XML-based CAD file format developed by Dassault Systèmes. It is primarily used for lightweight representation and exchange of 3D data, particularly within the Dassault Systèmes ecosystem, which includes software like CATIA, SolidWorks, and DELMIA. The format is designed to be easily embedded in documents and web pages, allowing for interactive 3D visualization without requiring large file sizes or specialized CAD software. 3D XML files can contain geometric data, product structure information, metadata, and even textures. They are often used for sharing product designs, creating interactive training materials, and enabling collaborative design reviews. The format supports various compression techniques to minimize file size, making it suitable for online distribution and viewing. While primarily associated with Dassault Systèmes products, some third-party viewers and converters are available to work with 3D XML files outside of the Dassault ecosystem. The format is intended to be a more accessible and lightweight alternative to heavier CAD formats like STEP or IGES, focusing on visualization and collaboration rather than detailed engineering analysis.