Stellarium - Stellarium is a free open source planetarium for your computer.
Google Sky Map - Google Sky Map is a free hand-held planetarium that allows you to identify stars, planets and more.
Sky Guide - A window to the stars has never been more beautiful and easy to use.
Code NASA - 253 NASA open source software projects
SkyView - SkyView is powerful, easy-to-use app that answers questions about stars, constellations, and more.
Open NASA - NASA data, tools, and resources