Application of old Comenius credo “Schola Ludus” ‐ school by play ‐ is found in current multimedia educational games in a classroom.However, it is essential that educational games can be operated on multiple platforms and devices.Since the beginning of the current millennium, the Internet and mainly world‐wide‐web based technologies and standards are widely adopted by different types of user computing devices ‐ i.e. smartphones, tablets, and computer desktops regardless of the operating system on them.Internet browsers (or web browsers) have been changing dramatically in the last few years and have been adopting and implementing web‐based standards and APIs.Recently, we have created a new technology combining some of the current web standards including Web‐Assembly for fast computation of mathematical models, web components for creating independent transferable objects, WebGL for involving 3D graphics. Additionally, we have created a tool for composing educational applications, which might include a simulator that runs in a web browser on all platforms and operating systems. Our tool and related technology are called BodyLight.js. An article about BodyLight.js was published in the Journal of Internet Medical Research ( https://www.jmir.org/2019/7/e14160/).BodyLight.js ( https://bodylight.physiome.cz/) is still in active development offered as open‐source software and opens up the possibility for creating a whole new kind of electronic publication linking hypertext, multimedia, and web‐based simulation games. Bodylight.js enables the creation of next‐generation electronic textbooks that use a computer, tablet or smartphone not only as a display device but as a simulation tool accompanying interpretation through simulation games and interactive images driven by a mathematical model in the background.One of the first applications created by this technology is the simulation of the integrated physiology of blood gas exchange, cardiovascular disorders, and acid‐base balance. We have been testing this application in the lectures of pathological physiology. It seems that the inclusion of a set of simulators significantly improves understanding of this non‐trivial topic by students compared to traditional forms of teaching.Support or Funding InformationMPO TRIO FV20628, MPO TRIO FV30195The key software tool for web application design is Composer. Composer is a web application ‐ an interactive design tool that educators, graphics designers, and modelers work with. It allows to visually create an HTML simulator, that can be used on any browser capable device.Figure 1Pressure‐volume loop simulator was developed using Bodylight.js software tool. The model‐controlled image displays atrial and ventricular filling, as well as valve opening and closing during the cardiac cycle. Students can pause the simulation and track the names of the cardiac cycle phases, atrial and ventricular pressures and volumes, pulmonary artery, and aortic pressures, and the current point on the pressure‐volume loop.Figure 2