Listed here are applications that provide mapping and spatial analysis functionality in a no-cost software application.
BASINS 4.0 is an environmental modeling interface built upon the open source GIS MapWindow. The system contains tools to download data from the internet and can perform basic GIS functions to prepare inputs for modeling pollutant loading in streams. There is also a Windows-based Climate Assessment Tool, for assessing potential impacts of changing climate on stream flows and pollutant loads. BASINS 4 also has the ability to transfer and share GIS standard data (shapefile, dbf, and GeoTiff) between other licensed GIS software.
DIVA-GIS is free GIS application that is used for many different purposes. You can use it to make shapefiles, grid data, and satellite images. DIVA-GIS is particularly useful for mapping species distribution, and for analyzing these data in various ways.
ESRI’s Explorer Applications
Download your choice of free applications from ESRI: ArcGIS Explorer, ArcWeb Explorer and ArcExplorer.
FlowMap is a freeware application designed to analyze and display flow data. This application was developed at the Faculty of Geographical Sciences of the Utrecht University in the Netherlands.
GMT – Generic Mapping Tools
Generic Mapping Tools (GMT) is a free, public-domain collection of ~60 UNIX tools that allow users to manipulate (x,y) and (x,y,z) data sets (including filtering, trend fitting, gridding, projecting, etc.) and produce Encapsulated PostScript File (EPS) illustrations ranging from simple x-y plots through contour maps to artificially illuminated surfaces and 3-D perspective views in black and white, gray tone, hachure patterns, and 24-bit color.
GRASS is probably the most well-known and original GIS software applications. GRASS is a raster-based GIS, vector GIS, image processing system, graphics production system, data management system, and spatial modeling system. GRASS can be downloaded for free.
SPRING is a GIS and Remote Sensing Image Processing system with an object-oriented data model which provides for the integration of raster and vector data representations in a single environment.
Freeware application developed by Tim Hirrell for vector based spatial analysis including Thiesson polygons, buffering, contour generation. Import and export shapefiles and CSV file formats.
TNTlite is a free version of TNTmips, TNTedit, and TNTview for small-scale projects. TNTlite is not a demo, but a large, full-featured geospatial analysis software package.
uDig is a Free, Open Source GIS desktop application that runs on Windows, Linux and MacOS. uDig was designed to use OGC’s OpenGIS standards such as WMS, WFS and more. One-click install allows you to view local shapefiles, remote WMS services and even directly edit your own spatial database geometries.