This is an unofficial repository of Swiss Ephemeris sources in all available programming languages.
Swiss Ephemeris is a software toolbox for programmers of astrological software. It is of little use for a non-programmer.
Swiss Ephemeris is built according to the highest standards of precision available in astronomical data. It is able to reproduce the ephemeris data in astronomical standard books up to the last printed digit.
Detailed information is available at https://www.astro.com/swisseph/ and in the documentation files in this repository.
It is possible to use Swiss Ephemeris without the ephemeris files. If the program finds no ephemeris files, it uses the builtin analytical ephemeris which provides "only" a precision of 0.1 arc seconds for the planets and 3" for the Moon. No asteroids will be available, and no barycentric option can be used.
The Swiss Ephemeris can be licensed by programmers to include this calculation engine in their software. Depending on your application the free edition under the Public License may apply, or you may have to acquire a professional license for a fee. More information is found at Astrodienst AG website.