"If I have seen further than others, it is because I have stood on the shoulders of giants..."
Library License About wxWidgets
LGPL-style Portable GUI library, free for every platform. Some porting issues, see Porting wxWindows Icons. The library size can be reduced by turning off features we don't need: see Shrinking wxWindows on Win32. GDAL / OGR MIT/X GDAL for raster formats, OGR for vector formats. PROJ.4 MIT Cartographic Projections Library, like GCTPC, but newer and cleaner Shapelib LGPL or MIT-style Read/write ESRI Shapefiles (bundled into GDAL) libgeotiff 'X style license' Read/write GeoTIFF files (bundled into GDAL) libpng/zlib custom Read/write PNG files and Gzip-compressed files. libcurl
MIT/X Client-side URL transfer library, supporting FTP, HTTP, and related protocols. libMini
LGPL CLOD library by Stefan Röttger, also does paging of large elevation/texture data via tilesets. NetCDF custom Reads the CDF format OpenSceneGraph (OSG)
custom Portable 3D scene-graph library. Besides basic scene graph functionality, it also provides the VTP with an art path, via .3DS and other 3D model formats. QuikGrid LGPL By John Coulthard. Reads a set of scattered data points, generates a grid, then display the surface as a contour map. OpenGL
3D rendering, both directly and indirectly through the scene-graph library.
Other Potential Libraries