SketchyPhysics is a plugin for Google Sketchup (Windows Only). It combines a simple and easy to use interface with the power of a fast and accurate physics library, the Newton SDK.
http://code.google.com/p/sketchyphysics
This is LEGO Digital Designer. The program that lets you build with LEGO bricks on your computer.
http://ldd.lego.com
Yenka is a new generation of educational modelling software from Crocodile Clips, which lets you simulate concepts and create content easily.
http://www.yenka.com
Welcome to Cyber Nations, a free persistent browser-based nation simulation game. Create a nation and decide how you will rule your people by choosing a government type, a national religion, tax rate, currency type, and more.
http://www.cybernations.net
It's a "what if?" game What if there was an oil crisis?
http://www.worldwithoutoil.org/metaabout.htm
