There are several types of geographic information system (GIS) programs available online as freeware applications. These programs are designed for mapping and spatial data analysis. Different types of GIS freeware are available for analyzing and displaying flow data, producing contour maps and processing remote sensing images.
A well-known GIS freeware application is the Geographic Resources Analysis Support System (GRASS). This geographical information system tool is a raster-based, vector GIS. Originally developed by the U.S. government, it is a free download that can process images, produce graphics and manage data. The GRASS download also includes a spatial modeling application.
FlowMap® is another GIS freeware application that a GIS technician or GIS analyst may use. Its main utility is analyzing and displaying flow data. The flow data can represent the movement of people, goods or services. FlowMap® was created in the Netherlands by faculty of the geosciences at Utrecht University.
For remote sensing imaging GIS freeware, SPRING may be the ideal application. Developed as a product of Brazil’s National Institute for Space Research, SPRING can process remote sensing images and produce an object-oriented data model. The data model effectively integrates raster and vector images in a single environment. Useful applications of this type of GIS freeware include environmental, socioeconomic and urban planning projects. The SPRING download is free for registered users.
Another type of GIS freeware is uDig, a user-friendly desktop Internet GIS. The graphical interface makes this application seemingly familiar for GIS users. Written using Java®, uDig provides a solution for viewing, editing and manipulating GIS data. A one-click download makes this a must-have GIS freeware application for viewing shape files and editing spatial database geometries.
A simple mapping and GIS tool is available as a free download in AGIS. The download is simple and the tutorials are easy to follow, even for the beginning GIS user. Primarily designed for cartography uses, AGIS streamlines the process of putting information into maps. It is specifically designed to be easy to use, making it a viable alternative to intensive GIS training. The maps produced with AGIS are vector-based, scalable and can be animated using a built-in scripting language.
Anything from mapping to spatial data modeling to managing flow data can be achieved with a GIS freeware application. GRASS and uDig are fairly comprehensive and can accomplish a variety of tasks. FlowMap® and AGIS have specialized uses for handling flow data and creating maps, respectively. SPRING is great for remote-sensing projects. There are many others available depending on exactly what the user needs to accomplish and what operating system is in place.