O2OO reads sensor data from a car into a sqlite database and generates graphs of the data so you can analyze the behavior of the car. It can also retrieve the location from a GPS module and store it in the same database, then can create a Google Maps KML-file, coloring the route line with a color depending on a sensor reading.
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.