PhET Interactive Science Simulations : "PhET Interactive Simulations is an ongoing effort to provide an extensive suite of simulations to improve the way that physics, chemistry, biology, earth science and math are taught and learned. The simulations are interactive tools that enable students to make connections between real life phenomena and the underlying science which explains such phenomena. Our team of scientists, software engineers and science educators use a research-based approach - incorporating findings from prior research and our own testing - to create simulations that support student engagement with and understanding of scientific concepts."
Science Simulations: "This site includes a collection of simulation links in math, physics, chemistry, earth science, and biology. The site offers some good models that help students explore difficult concepts or principles in science or reinforce their understanding of the learned concepts. In the area of biology, many interesting simulations links are included. These are cell simulations, virtual cell, biology in motion, virtual microscope, osmosis and membrane transport, interactive biology, virtual frog dissections, genetics simulations, and virtual knee surgery. Some of the sites require that you download the shockwave player or other software before interaction."
Schlumberger Excellence in Education Development: "SEED has produced virtual experiments and science-oriented games with nice graphic interfaces that permit changing key variables and seeing what happens.