PostGIS adds support for geographic objects to the PostgreSQL object-relational database. In effect, PostGIS "spatially enables" the PostgreSQL server, allowing it to be used as a backend spatial database for geographic information systems (GIS).
OpenStreetMap is a free editable map of the whole world. It is made by people like you.
OpenStreetMap allows you to view, edit and use geographical data in a collaborative way from anywhere on Earth
Vielversprechend aber nicht vollständig
L. Stenneth, O. Wolfson, P. Yu, and B. Xu. Proceedings of the 19th ACM SIGSPATIAL International Conference on Advances in Geographic Information Systems, page 54--63. New York, NY, USA, ACM, (2011)