X-Plane related

http://developer.x-plane.com/

http://www.alpilotx.net/

http://www.xpluginsdk.org/python_interface_downloads.htm

http://www.xsquawkbox.net/xpsdk/docs/DataRefs.html

http://b58.svglobe.com/data.html

http://www.nuclearprojects.com/xplane/xplaneref.html

Open Source libraries

https://www.python.org/

http://www.numpy.org/

http://scipy.org

http://www.gdal.org/

http://www.imagemagick.org

Useful forums, blogs, cookbooks and tutorials

http://geospatialpython.com/

https://github.com/dwtkns/gdal-cheat-sheet

https://pcjericks.github.io/py-gdalogr-cookbook/

http://gis.stackexchange.com/

http://www.gaia-gis.it/gaia-sins/spatialite-sql-4.3.0.html

http://geoexamples.blogspot.com.es/

http://www.toptal.com/python/computational-geometry-in-python-from-theory-to-implementation

Data

http://earthexplorer.usgs.gov/

http://openstreetmapdata.com/data/water-polygons

http://www.viewfinderpanoramas.org/dem3.html

Misc

http://www.forgottenairfields.com/