On-line calculator for the position of the sun. Appears to be written in Frink https://futureboy.us/frinkdocs/, a language which can evaluate expressions with units.

Links and recommendations for books about astronomical algorithms.

PyEphem provides scientific-grade astronomical computations for the Python programming language. Given a date and location on the Earth’s surface, it can compute the positions of the Sun and Moon, of the planets and their moons, and of any asteroids, comets, or earth satellites whose orbital elements the user can provide. Additional functions are provided to compute the angular separation between two objects in the sky, to determine the constellation in which an object lies, and to find the times at which an object rises, transits, and sets on a particular day.

The numerical routines that lie behind PyEphem are those from the wonderful XEphem astronomy application, whose author, Elwood Downey, generously gave permission for us to use them as the basis for PyEphem.

Author of the Antikythera mechanism emulator, interesting papers and books about programming and winner of the obfuscated C contest.

A colleague discovered two minor planets.

Interesting site about (amateur) astronomy.

Lots of information about photography (analogue and digital), including discussion about eye sensitivity.

A cool page for tracking satellites on a map from Google.

Manufacturers page, with links to software.