Ultimaker's software Cura 2.3 is using X3D files to define models allowing you to include color, geometry and material properties which the current widely used STL format does not support. These features are critical to the success of consumer grade 3D printing operations. The metadata features of the X3D standard allow model information to be stored alongside geometry and material properties; and the same X3D file can be used for interactive 3D graphics on the web and as the source file for 3D printing.

When data is presented in an X3D file it can be visualized with X3D players available over all platforms. Geometric data and metadata can be written and read with open, non-proprietary tools.  X3D acts as a central hub that can route engineering/3D model information between diverse 3D applications. There are several workflows and tools to import and export data between X3D and other open and proprietary formats.

More information about Cura 2.3 and Ultimaker is available here