How do I use and implement GML?

To begin using GML, you must first have a sound understanding of XML. You should then turn your attention to the conceptual model that underlies GML, which is described in the OGC Abstract Specifications.

The OpenGIS® Geography Markup Language (GML) Implementation Specifications.

Note This specification is neither a quick nor a simple read, but the benefits of using GML far outweigh the initial time and resources you and your organization devote to the task.

An overview of the specification is available on the GeoConnections website.

OGC-compliant web feature servers create GML by definition. The GeoConnections Discovery Portal provides a list of OGC-compliant WFS.

GML schemas and instances can be created by hand using a text editor, or better yet an XML-aware editor.


Many vendors have created client programs that create and/or consume GML. A list of GML client programs is available at the Geoconnections site.