GeographicLib is a small C++ library for: geodesic and rhumb line calculations; conversions between geographic, UTM, UPS, MGRS, geocentric, and local cartesian coordinates; gravity (e.g., EGM2008) and geomagnetic field (e.g., WMM2020) calculations. The emphasis is on returning accurate results with errors close to round-off (about 5–15 nanometers). Accurate algorithms for Geodesics on an ellipsoid of revolution and Transverse Mercator projection have been developed for this library. The functionality of the library can be accessed from user code or from the Utility programs provided. This library is not a general purpose projection library nor does it perform datum conversions; use PROJ instead. NOTE - This SlackBuild installs the following data sets: egm96-5 (geoid), egm96 (gravity) and wmm2020 (magnetic), provided that they have been downloaded and placed in the SlackBuild's directory, along with the source tarball. Several other data sets are available on the project's website, or can be downloaded and installed automatically by using the following scripts, after installation of the package: /usr/sbin/geographiclib-get-geoids /usr/sbin/geographiclib-get-gravity /usr/sbin/geographiclib-get-magnetic