Aciqra (Version: 2.2 tested) is an open source planetarium software. It is one of the more complete ones available. It features star catalogs and NGC and IC catalogs that include millions of stars and 1000s of deep sky objects such as galaxies. It offers corrections for atmospheric refraction and other enhancements to be as accurate as possible in tracking stars and other objects. It also provides extra information on objects such as asteroid and comets and events such as eclipses.
The interface of the program is not the best but it does try to stay true to the claim that