General aspects on GIS and RS software
A variety of GIS and RS software packages is available on the market. They may be categorized according to two sets of criteria:
1) The license terms, visibility of the source code and distribution policy
- proprietary software packages do not allow to view the source code of the funcionalities. Therefore, further development of the software is only conducted within the company owning and distributing the product. Use of the GIS software is coupled to the purchase of a licence for single users or organizations. License fees are often paid on an annual basis.
- Open Source software packages: the source code is accessible, so that anyone can contribute to the further development or design additional modules serving for her or his specific needs. Usually, there is a community developing the software. Open Source software packages are often (but not always) distributed under the GNU General Public License, meaning that they are free, but certain rules must be followed when distributing work building on the software. Most OpenSource software packages were designed for UNIX sytems, but they are increasingly adaptred to the Windows environment. The Open Source Geospatial Foundation (OSGeo), which coordinates much of the software development, provides a comprehensive list of Open Source GIS software packages.
2) The functionalities offered by the software
- specialized software: many GIS software packages are specialized to a certain set of functionalities, e.g. raster analysis, vector analysis, processing of remotely sensed data, display of maps, online map services or the integration of databases. This is particularly true for many Open Source GIS software packages.
- comprehensive software: some packages offer a wide range of functionalities. Most of them have started with a certain set of functionalities a long time ago, which are still the core of the software today. ArcView, and later ArcGIS, for example, were originally designed for vector analysis, but extensions were added to allow operations on raster data.
Selected software packages
The below list contains a selection of software considered to be useful for application in geosciences. It is not complete, and many specialized software packages are disregarded. Such include, for example, databases, Web GIS software or programs for field computers and GPS. Particularly the latter are extremely useful for geological field work, a topic not covered by the present training course.