Duolingo - Duolingo is a free language learning app for iOS, Windows and Android devices. The app makes learning a new language fun by breaking learning into small lessons where you can earn points and move up through the levels. Read more about Duolingo.
Space Engine - Space Engine is a realistic virtual Universe you can explore on your computer.
Memrise - Learn a new language with games, humorous chatbots and over 30,000 native speaker videos.
Celestia - Real-time 3D visualization of space
Busuu - Join the global language learning community, take language courses to practice reading, writing, listening and speaking and learn a new language. Learn English with busuu's .
Stellarium - Stellarium is a free open source planetarium for your computer.