Free Open Source Software (FOSS)
Desktop Geographic Information Systems (GIS) Programs

FWTools     

FWTools is a set of Open Source GIS binaries for Windows (win32) and Linux (x86) systems produced by Frank Warmerdam (ie. FW). It was previously known as OpenEV_FW. The kits are intended to be easy for end users to install and get going with. No fudzing with building from source, or having to collect lots of interrelated packages. FWTools includes OpenEV, GDAL, MapServer, PROJ.4 and OGDI as well as some supporting components. The FWTools kits also aims to track the latested development versions of the packages included as opposed to official releases. While this may mean the packages are less stable, it is intended to give folks a chance to use the latest and greatest. FWTools releases also are a means by which Frank make recent development version bug fixes available to a wider audience than would be prepared to build them from the source.

GRASS     

The Geographic Resources Analysis Support System (GRASS) is a Geographic Information System (GIS) used for spatial modeling, visualization of both raster and vector data, geospatial data management and analysis, processing of satellite and aerial imagery, and production of sophisticated presentation graphics and hardcopy maps. GRASS combines powerful raster, vector, and geospatial processing engines into a single integrated software package. The GRASS GIS project is developed under the terms of the GNU General Public License (the GPL) by volunteers the world over. GRASS differs from many other GIS software packages used in the professional world in that it is developed and distributed by users for users, mostly on a volunteer basis, in the open, and is given away for free. Emphasis is placed on interoperability and unlimited access to data as well as on software flexibility and evolution rate. The source code is freely available allowing for immediate customization, examination of the underlying algorithms, addition of new features, and fast bug fixing.

gvSIG     

gvSIG is free and open source (GNU/GPL) desktop GIS strongly oriented to manage geographic information and towards Spatial Data Infrastructures (SDI). It is characterized by a user-friendly interface, with a quick access to the most common GIS and CAD file formats both vector (shp, dgn, dxf, dwg, gml, etc.) and raster (ecw, mrsid, tiff, img, jpg2000, etc.) and furhermore it's able to connect with all kind of geodata through remote services like WMS, WFS, WCS, JDBC (geodatabases). Catalogue and gazetteer services can be used too with gvSIG.

MapWindow     

The MapWindow application is a free, extensible, geographic information system (GIS) that can be used in many ways: 1) As an alternative desktop GIS, 2)To distribute data to others, 3)To develop and distribute custom spatial data analyses. The MapWindow application is a ready-to-use spatial data viewer, and a tool that can be modified into a new custom application. Customization is done by editing the MapWindow Configuration File, and/or a MapWindow Project File. These are the two files that control the look and feel of MapWindow. Both are XML-format files that can be edited directly through notepad or an XML editor.

Quantum GIS     

Quantum GIS (QGIS) is a user friendly Open Source Geographic Information System (GIS) that runs on Linux, Unix, Mac OSX, and Windows. QGIS supports vector, raster, and database formats. QGIS is licensed under the GNU General Public License. QGIS lets the user browse and create map data on their computer. It supports many common spatial data formats (e.g. ESRI ShapeFile, geotiff). QGIS supports plugins to do things like display tracks from a GPS. QGIS is Open Source software and its free of cost.

Saga      

SAGA – System for Automated Geoscientific Analyses- is a hybrid GIS software. The first objective of SAGA is to give (geo-)scientists an effective but easy learnable platform for the implementation of geoscientific methods, which is achieved by SAGA's unique Application Programming Interface (API). The second is to make these methods accessible in a user friendly way. This is mainly done by the Graphical User Interface (GUI). Together this results in SAGA's true strength: a fast growing set of geoscientifc methods, bundled in exchangeable Module Libraries.The figure shows SAGA's system architecture.

uDig      

The User-friendly Desktop Internet GIS (uDig) is both a GeoSpatial application and a platform through which developers can create new, derived applications. uDig is a core element in an internet aware Geographic Information System.