Use of ICT can provide many opportunities for physics education, and one of these opportunities is a use of physics simulations. Physicists professionals use complex simulations to solve real world problems, but for educational use simulations/animations not always have to be so complex. More lightweight simulations and animations can be used. Such simulations usually are more easily distributable through the Internet. Simulations and animations are important in physics education because they can help to visualize different physical processes and to provide some interactivity. This paper is focusing on a use of Physlets – small portable Java Applets, which can be used to simulate and animate different physical phenomena. The purpose of this paper is to give a brief overview of Physlets and to demonstrate in few examples the possibilities of adaption and customization of Physlets in the learning material. Keywords: Physlets, Educational physics simulations.