Nightfall is an astronomy application for fun, education, and science. It
can produce animated views of eclipsing binary stars, calculate synthetic
lightcurves and radial velocity curves, and eventually determine the
best-fit model for a given set of observational data of an eclipsing binary
star system.  It is, however, not able to fry your breakfast egg on your
harddisk. ;-)

WWW: http://www.hs.uni-hamburg.de/DE/Ins/Per/Wichmann/Nightfall.html