Where 2.0: Standards

As the number of mapping platforms increases, standards start to be more important. If upcoming wants to offer access to its database for people to include in their own mashups or applications, what data format or web services API standards should they adhere to? Upcoming has chosen to use GeoRSS, a light-weight standard rapidly gaining traction. But there are others ...

GeoRSS arose out of this need to share lists of points. Google Earth had a similar need several years ago, and created KML (Keyhole Markup Language) for its particular needs. KML is like GeoRSS, but with camera angles, styles, overlays, and many other presentation features built in. There is, naturally, a small religious element to any discussion of whether a feature markup language should have styles included or whether they should be separate (a-la CSS).

GeoRSS and KML are data interchange file formats. The Open Geospatial Consortium standards defines the GML format, which KML bears some resemblance to. KML is notorious for being a superset of features of the products whose companies worked together to define the format. This means that it's complex and quite scary--KML is more accessible, and GeoRSS even more so.

The OGC also defines several web services: WFS (Web Feature Service) and WMS (Web Mapping Service) are the two big ones. WMS describes the basic map (either as tiles or as lines) and WFS describes the features on that map. NASA Worldwind gets its imagery through WMS, and they're adding WFS support. It's the only one of the major Internet mapping paltforms (Google Earth, Google Maps, Yahoo! Maps, Virtual Earth, I'm looking at you) built on top of the OGC standards. There are hacks to get Google Earth to display WMS data, and if you buy the full Keyhole product then you get WMS display. I've also seen a smattering of Google Maps mashups with OGC standards.

Why are WMS and WFS important? Because all the traditional GIS applications support them, as do storage systems and analysis tools. When you graduate from a hack to really building location intelligence into your application, you'll want to start using some of these sophisticated tools. For example, you might want to start using PostGIS, the geospatial extensions to the popular PostgreSQL open source database so you can easily search by location. Or you might want to use the GRASS open source GIS for entry and analysis. Or, of course, you might buy commercial systems from ESRI, MapInfo, or others.

So open standards are important because they let you move from mashups to infrastructure. That's why we've scheduled talks on GeoRSS, the OGC activities, ESRI, and GRASS. NASA Worldwind will be there, Google are scheduled to speak and I know they want to talk about Google Earth, Yahoo! and Microsoft will be speaking around new features in their mapping platforms, and AutoDesk will be speaking about their standards-compliant MapGuide Open Source.