MaterialX is an open standard for representing rich material and look-development content in computer graphics, enabling its platform-independent description and exchange across applications and renderers. Launched at Industrial Light & Magic in 2012, MaterialX has been a key technology in their feature films and real-time experiences since Star Wars: The Force Awakens and Millennium Falcon: Smugglers Run. The project was released as open source in 2017, with companies including Sony Pictures Imageworks, Pixar, Autodesk, Adobe, and SideFX contributing to its ongoing development. In 2021, MaterialX became the seventh hosted project of the Academy Software Foundation. MaterialX addresses the need for a common, open standard to represent the data values and relationships required to describe the look of a computer graphics model, including shading networks, patterns and texturing, complex nested materials and geometric assignments. To further encourage interchangeable CG look setups, MaterialX also defines a large set of standard shading and processing nodes with a precise mechanism for functional extensibility.