Although GML is gaining support globally, there are still barriers to its adoption.
The Central IT unit of the U.K. government, which has standardized on document-tagging language XML, has also adopted GML 1.0 for exchanging geospatial data in its e-Government Interoperability Framework (e-GIF).
The U.S. Census Bureau has commissioned GML author Ronald Lake's company, Galdos Systems, to write a translator that will let GML users read the agency's extensive TIGER GIS database.
But some in the geographical information industry say they think GML's creators and supporters may be too ambitious and that they doubt the efficacy of one evolving standard built on another evolving standard.
Another sticking point is that there are actually two GMLs. One industry consortium, led by Tokyo-based NTT Data Corp., has developed Geography XML (GXML) to support location-aware services available via cell phones in Japan.
GML was created by Lake to support a broader range of applications and now involves other developers around the world.
Work on both standards has continued for two years concurrently but along diverging paths, and it was only at the Oct. 6 meeting of the OGC that the two groups agreed to work to merge the two during the next six to 12 months.
Twenty years ago, the issue would have been of interest almost solely to government agencies, by far the main users of GIS. Not so today.
By next October, U.S. phone carriers will be required by law to be able to identify the location of cell phone callers. Similar requirements are being considered for Europe.
GML is being built into other OGC standards that will facilitate such location-aware applications.
According to a report by San Jose-based Dataquest last year, "increased corporate use of GIS technology to improve customer service and cut costs is expected to help propel the overall market from US$862 million [in 1998] to US$1.7 billion in 2000."