GeoRSS is establishing itself as an easy and effective way to share and build maps. With the potential to make the most of the "RSS ecosystem" for the Geospatial Web, GeoRSS bridges the practices of GIS professionals and amateurs, web map hackers, and numerous services that enable location-based content.

Mikel Maron describes the extensions to RSS/Atom that let GeoRSS encode location in standard feed technology and looks at the current state of development and the services and tools using the format.

Wouldn't it be great if you could get job postings by area as RSS feeds? What about an RSS feed of all the accidents that took place recently along the route of your daily commute? For some years, there have been efforts to include geographic information in RSS. What started as an IRC chat led to the birth of the W3C's Geo Vocabulary, which provided a way to specify longitude and latitude information in RDF documents. This format evolved slowly and came to be called GeoRSS. However, today's GeoRSS bears little resemblance to that original format.

Last year at Where 2.0, Yahoo! announced support for GeoRSS. Following that, interested individuals came together to jumpstart an open process to hash out a baseline for GeoRSS. The goal was to support more geometries and to include altitude, while retaining simplicity. A subsidiary aim was to produce descriptive documentation that could then be endorsed by standards bodies such as the Open Geospatial Consortium (OGC) and the World Wide Web Consortium (W3C). So GeoRSS.org was formed, which led to a completely new encoding of GeoRSS with the same name.

GeoRSS is feed format neutral: RSS 1.0, RSS 2.0, RDF, Atom and even microformats are supported. And it's actively being used already for many good causes. In 2004, the USGS became the first organization to publish GeoRSS when it began broadcasting potential earthquake alerts as encoded RSS feeds. Following the 2005 tsunami disaster, the European commission JRC deployed an online tsunami simulator that subscribed to the USGS GeoRSS feed and ran tsunami simulations based on the epicenter and magnitutde information in the feed. The results of the simulation were then published in GeoRSS with polygon geometries indicating the extent of a tsunami wave, hour by hour.