Open Source Geospatial Foundation
http://osgeo.org/index.html
MapServer — UMN MapServer
http://mapserver.gis.umn.edu/
GRASS GIS
http://grass.itc.it/
GeoTools
http://docs.codehaus.org/-display/GEOTOOLS/Home/
DM Solutions Group
http://www.dmsolutions.ca/
MapTools.org
http://maptools.org
FreeGIS.org
http://www.freegis.org/
Open Source GIS
http://opensourcegis.org/
GisPython.org
http://www.gispython.org/
NTS NetTopologySuite
http://sourceforge.net/projects/nts
JTS Topology Suite
http://www.vividsolutions.com/-jts/jtshome.htm
SharpMap engine - .NET Mapping Engine
http://sharpmap.iter.dk/
