As part of my bachelor's thesis I dove into the possibilities of 3D and XR on the web with the help of ThreeJS. With what I learned I made a small demo in which a user can put their own PC build together with a selection of components, ensuring compatibility along the way. The goal was to ensure a great experience on both XR (here a Meta Quest) and non-XR devices, both due to time constraints I didn't quite get there. I got into detail on performance, the basics of 3D, different use cases, (dis)advantages of using these technologies, development obstacles, structuring a ThreeJS project... So enough material to fill 70 pages. While it was fun working with this library, I will definitely try React Three Fiber in the future, instead of plain ThreeJS.