Library to extract valid data from within an Open Street Map input file
https://www.gaia-gis.it/fossil/readosm/index

ReadOSM is an open source library to extract valid data from within an Open Street Map input file. Such OSM files come in two different formats:

- files identified by the .osm suffix simply are plain XML files.
- files identified by the .osm.pbf suffix does containt the same identical data, but adopting the Google's Protocol Buffer serialization format and thus requiring much less storage space.