The last 20 years have seen dramatic developments in GIS technology and geographical information science.Fierce competition and growing user demand has resulted in a number of high-quality solutions, which are largely responsible for the vast increase in the GIS marketplace.However, the vast majority of the industry solutions is aimed at supporting basic needs of capture, archival and visualization of spatial data.Recent technological advances have concentrated in issues such as user-friendly interfaces, interoperability across data repositories and spatial extensions of database technology.These developments have largely ignored recent advances in GIScience, which include research areas such as spatio-temporal data models, geographical ontologies, spatial statistics and spatial econometrics, dynamic modeling and cellular automata, environmental modeling, and neural networks for spatial data.
Moreover, GIS software development is bound to witness substantial change in the upcoming years, induced by technological advances in spatial databases. Current and expected advances in database technology will enable, in the next few years, the complete integration of spatial data types in data base management systems.This integration is bound to change completely the development of GIS technology, enabling a transition from the monolithic systems of today (that contain hundreds of functions) to a generation of spatial information appliances, small systems tailored to specific user needs. Coupled with the data handling capabilities of new generation of database management systems, rapid application development environments will enable the construction of "vertically-integrated" solutions, directly tailored to the users' needs.Therefore, an important challenge for the GIS community is finding ways of taking advantage of the new generation of spatially-enabled database systems to build "faster, cheaper, smaller" GIS technology.
One of the possible responses to this challenge would be to establish a co-operative development network, based on open source technology.In a similar approach as the Linux-based solutions, the availability of GIS open source software would allow researchers and solution developers access to a wider range of tools than what is currently offered by the commercial companies.A second important reason for developing open-source spatial analysis tools is the need to resolve the "knowledge gap" in the process of deriving information from images and digital maps.This "knowledge gap" has arisen because our capacity to build sophisticated data collecting instruments (such as remote sensing satellites, digital cameras, and GPS) is not matched by our means of producing information from these data sources. To a significant extent, we are failing to exploit the potential of the spatial data we collect.For example, there are currently very few techniques for image data mining in remote sensing archives, and thus we are failing to use the information available in our large earth observation data archives.
Therefore, the geographical information community would have much to benefit from the availability of a general open source GIS library.This resource would make a positive impact by allowing researchers and solution developers access to a wider range of tools than what is currently offered by the commercial companies.In a similar approach to the Linux and subsequent open source software efforts, we recognize that such development does not happen by spontaneous growth, but needs a core set of technologies from which further developments may happen. This co-operative GIS and image processing software environment would allow researchers to share their results with the EO community, thus reducing the "time to market" from academia to society.As an example of such products, a group of R&D institutions in Brazil is currently developing TerraLib, an open-source GIS library that enables quick development of custom-built applications for spatial data analysis (the software is available at www.terralib.org). As a research tool, TerraLib aims to enable the development of GIS prototypes that would include recent advances in GIScience.On a practical side, TerraLib enables quick development of custom-built applications using spatial databases. TerraLib aims to improve on such capabilities, by providing direct access to a spatial database, without unnecessary middleware.We believe that projects such as TerraLib show that open source GIS projects can make substantial contributions to the spatial information community, by providing a platform for innovation and collaborative development.