GRASS (the Geographic Resources Analysis Support System) is a software raster- and vector-based GIS (Geographic Information System), image processing system, graphics production system, and spatial modeling system. It contains many modules for raster data manipulation, vector data manipulation, rendering images on the monitor or paper, multispectral image geocoding and processing, point data management and general data management. It also has tools for interfacing with digitizers, scanners, and the PostgreSQL, DBF, and ODBC connected databases. GRASS operates on all common operating systems.
GraphPak is a programming library of 2D and 3D charting objects for the Qt toolkit. It provides software developers with a set of C++ objects to easily create charts or graphs that aid in the visual presentation of technical and business data. This release includes Bar, Line, Pie, Ring, Area, Hi-Lo, Box and Whisker, and Polar charts. It is based on the KD Chart product from Klarälvdalens Datakonsult AB.
The OGR Simple Features Library is a C++ library providing read/write support for a variety of Geospatial (GIS) vector file formats including Shapefiles, Mapinfo MID/MIF and TAB, PostGIS, and Oracle Spatial. It attempts to follow an OpenGIS Simple Features geometry model, and use OpenGIS coordinate system standards. C and Python bindings are provided. It is a component of the GDAL project.
Tkgeomap is a set of extensions to the Tcl/Tk scripting language for accessing, manipulating, and displaying geographic data. The extensions add commands that perform basic cartographic calculations, define and use projections, store data in lines and as named places, and display the data in canvas widgets.
GEOS is a complete C++ implementation of the functions and predicates defined in the OpenGIS "Simple Features for SQL" specification. It includes high quality implementations of all the important spatial relationships and operations, robust versions of all functions in the dimensionally extended 9 intersection predicate model, implementations of the operators, Buffer(), Union(), and Intersection(), and all other SFSQL functions including Area(), Length(), Centroid(), etc.
The GPSTk provides both fundamental and advanced GPS processing algorithms. A wide array of functions are provided by the library, notably RINEX I/O, ephemeris calculation, atmospheric refraction models, and positioning algorithms. GPSTk applications provide more concrete benefits to the user, including cycle slip detection and removal, calculation of the Total Electron Content (TEC) of the ionosphere, and RINEX file manipulation.