Vokabel 

Vokabel is a free vocabulary-training program. Just write the words you want to learn and let the program test you. The program has intelligent functions that help you focus on words you don't know so well.
vokabel vocabulary training english french german spanish

3D Chemical Elements ScreenSaver 

Have you ever imagined the smallest bricks of the Universe - all that atoms with their protons, neutrons, electrons and quarks? With this 3D Screensaver you have the unique opportunity to see how they look like in reality with amazing visual effects.
screen saver screensaver desktop 3d mendeleev chemical element atom electron proton neutron nucleus