ruby-sphere-0.2.1 released

ruby-sphere is an application to calculate apparent positions of stars with a moderate accuracy. We are pleased to announce the third alpha release, ruby-sphere-0.2.1, which is a bug fix to the previous release: the executable script `visibility' was missing ;( You can now really edit a simple text file to plot your visibility map.

The goal of ruby-sphere is to to provide an easy way to plan astronomical observations. Ruby version 1.8.x is required. Gnuplot is required to plot visibility maps.