The OGC Announces GML 4.0 (Geography Markup Language) Workshop

Wednesday, 27 July 2011 UTC

27 July 2011 - The Open Geospatial Consortium (OGC®) and the OGC GML Working Group (WG) invite interested parties to attend a one-day workshop on GML 4 on September 19th in Boulder, Colorado. The workshop is organized as part of the September OGC TC meeting, but is open to non-OGC members.

The current approved version of GML is GML 3.2, which is identical to ISO 19136:2007. An official call for GML change requests was completed in 2008. The GML WG approved several of these change requests for the release of GML 3.3 later this year. GML 3.3 is an extension to GML 3.2 and will be fully backwards compatible with GML 3.2.

Many communities and organizations use GML. Therefore, creating version 4.0 is not undertaken lightly. Besides a number of pending change requests to be considered by the GML Working Group, GML 4.0 is also required to comply to the OGC’s new modular specification policy. One of the key challenges of the revision will be the identification of a modular structure for GML.

Before starting work on GML 4.0, the GML Working Group wants to have a clear idea about the demand for such a version, what the goal and characteristics of this new version should be and how the OGC can best address the requirements of existing and potential users. In order to get a better understanding of the needs and expectations of user communities and developers both inside and outside of the OGC membership, the workshop will be open to anyone interested in participating. Representatives from other OGC Working Groups, existing user communities, OSGeo, developers and ISO/TC 211 members are encouraged to attend.

The goal of the workshop is to get input and guidance from the GML user community for the development of GML 4.0. The workshop should result in a set of guiding principles the GML Working Group can use in the process of designing the next version of the standard.

Interested parties are encouraged to provide statements in advance, outlining their opinion on the subject. These statements will be used to prepare the meeting so that we can get maximum use out of the workshop. Statements could address issues such as:

  • Positioning of GML 4.0. The current understanding is that GML 4.0 should not replace GML 3.2/3.3 and that existing community encodings with specific application support will likely continue to use GML 3.x.
  • Key features of GML 4.0 that would justify developing and publishing a new version of GML.
  • The modularization of GML, making it easier to pick and choose parts of GML that are relevant in a certain context. For example, the current schema could be structured in about 20 modules, generally along the lines of the current schema documents. Alternatively, a more fine-grained structure could be designed and "profiles" (defined, for example, in a standard or by a community) would then be aggregations of these.
  • Making GML easier to implement and/or easier to use.
  • Solving current problems with GML that prevent successful use/implementation.

To attend, register at

Statements can be posted and viewed on the public OGC wiki:

The OGC is an international consortium of more than 415 companies, government agencies, research organizations, and universities participating in a consensus process to develop publicly available geospatial standards. OGC Standards support interoperable solutions that "geo-enable" the Web, wireless and location-based services, and mainstream IT. OGC Standards empower technology developers to make geospatial information and services accessible and useful with any application that needs to be geospatially enabled. Visit the OGC website at