Open-Source Software Gains Foothold

Users can tailor applications to fit their needs.

The landscape of open-source GIS software has changed significantly in the past couple of years, and the implications of those changes are still unfolding. Recent offerings from big-name players such as Autodesk and the National Aeronautics and Space Administration (NASA) apparently are lending credibility to open-source efforts worldwide and opening doors for more end users to participate in software development.

In general, software is considered open source if the source code is made available to the general public for modification and/or redistribution. The GIS arena has proven popular for open-source development as public domain data sources have grown and GIS has gained popularity across a wider spectrum of users.

Opening Up
One of the first open-source GIS applications to emerge was Geographic Resources Analysis Support System (GRASS), a tool originally developed by the U.S. Army Corps of Engineers for military land management and environmental planning. After the Corps stopped development of GRASS, it was picked up by the academic community in the late 1990s and has been enhanced as an open-source application by a variety of developers. It is used in both the private and public sector for data management, image processing, graphics production, spatial modeling, and visualization. More than one million lines of ANSI-C code are fully available for downloading.

MapServer, originally developed by the University of Minnesota in cooperation with NASA and the Minnesota Department of Natural Resources, also has gained recognition as an open-source application. It is maintained by approximately 20 developers around the world and is used primarily for rendering maps, images, and vector data on the Web.

Autodesk Joins
Autodesk officially entered the open-source scene in 2006, when it released code for its Autodesk MapGuide Enterprise Web-mapping product. The company still maintains a commercial version, which is largely derived from MapGuide Open Source. Both include an interactive viewer that supports feature selection, property inspection, map tips, and other tools.

Robert Bray, a geospatial architect for Autodesk in Calgary, Alberta, said the MapGuide development team initially had reservations about the open-source approach, but is "now very open and positive" about it. "We realized Web mapping had become commoditized," he said. "The real core value is providing solutions on top [of Web mapping]."

In July, Autodesk unveiled Autodesk MapGuide Enterprise 2008 and Autodesk Topobase 2008. The latter is targeted at utility companies and includes a customized module for the gas industry. It also incorporates the latest Autodesk MapGuide Enterprise and AutoCAD Map 3D capabilities.

Autodesk's entry into the open-source world a few years ago caught many GIS professionals by surprise, given the company's track record of protecting proprietary technology. But the company's participation appears to be beneficial on several fronts. "It provides marketing and legitimacy that wasn't there previously," says Sam Bacharach, executive director for outreach with the Open Geospatial Consortium, a nonprofit organization leading the development of standards for geospatial and location-based services. The combination of open standardized interfaces, open-source software, and public domain data is helping "provide functionality that was previously not available without buying software and data," he said.

Mapping Boulevard Mowing
The City of Nanaimo, British Columbia, has developed two internal applications that work with the MapGuide open-source platform. The city tracks its boulevard mowing activities with an application built in approximately six weeks, according to Jason Birch, senior applications analyst in the city's information technology office. The city did most of the development in-house, assisted by consultant SL-King.

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The City ofNanaimo, British Columbia , developed an application to track boulevard mowing. (Figure courtesy of the City of Nanaimo, B.C.)

"As we were beta testing [MapGuide OS], we saw a lot of value" in developing custom applications, Birch said. The mowing application allows field inspectors to enter mowing data on a laptop, report on contractor status, synchronize data in the office, and output information in MapGuide's SDF format and others.

The City of Nanaimo, assisted by consultant DM Solutions Group, also developed a cemetery mapping application that allows users to access records of cemetery plots, including location data not readily available in its conventional filing system. "This creates much more insight into the cemetery database," Birch said. The application is presently available only to city staff, but will be launched as a Web application later this year, he said.

MapGuide can be deployed on Linux or Windows and is accessible to developers working in PHP, .NET, Java, and JavaScript environments, with core development done in C++, according to Bray. One of the key attractions to developers is the ability to use FDO (feature data object) technology to manipulate and analyze geospatial information regardless of where it is stored.

Other Players
NASA has been participating in open-source GIS software for several years and recently announced plans to release a Java-based version of its World Wind application. World Wind users can access satellite imagery and elevation data to display 3D images virtually anywhere on Earth. World Wind development can also be done in .NET.

NASA's World Wind displays 3D images by combining satellite imagery with topographic data. (Figure courtesy of NASA.)

MetaCarta, a Cambridge, Massachusetts-based provider of GIS solutions, recently released an open-source version of OpenLayers, which allows users to place a dynamic map in any Web page, displaying map tiles and markers loaded from a variety of sources. MetaCarta developed the initial version of OpenLayers and gave it to the public to further its development. The company also introduced an open-source add-on called TileCache, which accelerates the serving of tiled maps on the Web.

Industry analysts foresee continuing evolution and maturation of open-source GIS software over the next few years, with development efforts mirroring larger GIS trends. "The big green fields are in telematics and tracking of all sorts, whether it be cars or cell phones or wild animals," said Paul Ramsey, director of Refractions Research, a GIS consulting firm based in Victoria, British Columbia. Wherever the demand for spatial data grows, open-source technology will likely play a part in the dissemination of the data.