Education

KidZui is a fun, intuitive, easy-to-use kids’ browser and kid-safe social network with over a million games, websites, pictures, and videos. Kids can connect with their friends on KidZui, express their feelings and opinions, and share cool stuff they find online. It’s a fun, safe, and engaging internet experience that rewards curiosity and builds independence.
Celestia free space simulation that lets you explore our universe in three dimensions. Celestia runs on Windows, Linux, and Mac OS X.
Medexam.net a free educational program for medical students and doctors. Medexam.net runs on Windows.
Dia is a gtk+ based diagram creation program released under the GPL license. It can be used to draw many different kinds of diagrams. It currently has special objects to help draw entity relationship diagrams, UML diagrams, flowcharts, network diagrams, and many other diagrams. It is also possible to add support for new shapes by writing simple XML files, using a subset of SVG to draw the shape.
Google Earth gives you a wealth of imagery, and geographic and astronomical information.
NASA World Wind is a graphically rich 3D virtual globe for use on desktop computers running Windows. It combines NASA imagery generated from satellites that have produced Blue Marble, Landsat 7, SRTM, MODIS and more.
SpeQ Mathematics is a small, extensive mathematics program with a simple, intuitive interface. All calculations are entered in a sheet. In there you can freely add, edit and execute all calculations. You can define variables and functions, and plot graphs of your functions. You can save your calculations for later re-use.
Stellarium is a free open source planetarium for your computer. It shows a realistic sky in 3D, just like what you see with the naked eye, binoculars or a telescope.