Counter-Strike - Counter-Strike is a PC-exclusive FPS video game developed by Valve Corporation.
Stellarium - Stellarium is a free open source planetarium for your computer.
Xonotic - Xonotic is a free (GPL), fast-paced first-person shooter that works on Windows, OS X and Linux.
KStars - KStars is a Desktop Planetarium for KDE.
Rage - Rage Software, also Rage Games and FX Digital Network, was a British video game developer.
SkyView - SkyView is powerful, easy-to-use app that answers questions about stars, constellations, and more.