B4R - Development tool for native Arduino programs.
Algodoo - Algodoo is a 2D simulator freeware product designed as a physics learning tool. It was originally created by Emil Emerfeldt as part of his master’s thesis in 2008. Read more about Algodoo.
Circuito.io - Instant code and wiring for your project
PhET Interactive Simulations - Founded in 2002 by Nobel Laureate Carl Wieman, the PhET Interactive Simulations project at the University of Colorado Boulder creates free interactive math and science simulations.
embedXcode - embedXcode is a template for Xcode.
LabsLand - LabsLand lets students access real educational laboratories through the Internet.