Yenka

Yenka is a suite of educational programs for teachers and students.
This program lets you experiment in a virtual environment with topics in electronics, mathematics, geometry, statistics, programming, chemistry and electricity.

This suite contains the following modules: Programming, Sequences, 3D Shapes, Statistics, Inorganic Chemistry, Electrochemistry, Light and Sound, Motion, Electricity, Basic Circuits, Electronics, PCBs with Electronics, PICs and Gears. Each program has an individual licence. The whole package is free for home users, who can obtain a free licence from Crocodile. A warning about the illegality of using the software in a school will be displayed at the left bottom of the screen. School users must buy a license for each product. Doing so will grant them free upgrades until July 2012. Once bought, the program can be used on any computer in your school.

Every program comes with lots of examples that you can use in your classes, modify as you want, and then save, using the proprietary .YKA format.