GML 3 is modular, meaning that users can select out only the parts necessary for use, which simplifies and minimizes the size of implementations.

The Open GIS Consortium (OGC) announced the approval and release of Geography Markup Language version 3 (GML 3). GML 3 defines a data encoding in XML that allows geographic data and its attributes to be moved between disparate systems with ease. The new release is modular, meaning that users can select out only the parts necessary for use, which simplifies and minimizes the size of implementations. New additions in GML 3 include support for complex geometries, spatial and temporal reference systems; topology; units of measure; metadata; gridded data; and default styles for feature and coverage visualization.

GML 3 is almost entirely backwards compatible with GML 2 so that developers and users familiar with GML 2 can begin working immediately with GML 3. Like GML 2, GML 3 will play a key role in both spatial data encoding and transport, and in the description of geographic objects for geospatial Web services.