I work on the PhET team to help design sims, use the sims in chemistry, physics and math classes at a high school. I have been a teacher for 30 years and worked with PhET since 2004. I write inquiry-based activities and clicker questions for many sims. Presently, I have about 115 activities on the open source teaching ideas. Last year, there were over 600,000 downloads of my activities. I also hold workshops for using PhET and clickers too.PhET is a Creative Commons License group. The simulations are available to use online or they can be downloaded and are translated into many languages. There are over 600 activities that teachers have shared for other teachers to use or adapt.