Toolkit for working with and mapping geospatial data
GeoTools is an open source (LGPL) Java code library which provides standards compliant methods for the manipulation of geospatial data.
GeoTools is an Open Source Geospatial Foundation project.
The GeoTools library data structures are based on Open Geospatial Consortium (OGC) specifications.
Geodesy based library (geodetic and geocentric functions)
geoStarsLib has functions for dealing with many geodesy-based problems found in positioning, pointing, and surveying situations. It is useful to determine absolute position on the earth, pointing vectors, coordinate transformations, and other functions.