Geolocator is a PHP class which provides an easy-to-use interface to the IP address location XML API described at ipinfodb.com. This API allows you to find the city, state/region, country, and approximate latitude/longitude associated with an IP address or domain. The class aims to be easy-to-use, versatile, and well-documented. The class requires PHP 5.30 or greater, compiled with cURL support.
Quantum GIS (QGIS) is a cross-platform Geographic Information System (GIS). It offers support for vector and raster formats, including spatially enabled tables in PostgreSQL using PostGIS, common GIS vector formats such as Shapefiles, and geo-referenced rasters (TIFF, PNG, and GEOTIFF). Many plugins are available to dynamically add new functionality. Viewing of GRASS layers (vector and raster) is provided by a plugin. GRASS vector layers can be edited in QGIS.
GeoQO is a waypoint, geocaching, and waymarking database. It is extremely fast and offers a wide variety of utilities for manipulating waypoints. Though designed for geocaching and waymarking, it should be usable for any waypoint management. It is highly extensible; writing new import, export, search, display, and other plugins is easy to do.
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.
geoCtools manipulates geo-data in CSV or KML files. It generates KML files for Google map/earth. Polygons can be merged, locations (icons) added with user data in the balloons, and selected via FIPS code. It uses libxml2. It is command-line driven. It contains data for US states down to the county level. It has optional data for PC(USA) denomination.