The entire project, including code and website, is in the public domain to make it available to as many as possible. All code can be found on GitHub. Feel free to contribute to the simulation code as well as to the website.
There's no paywall, advertisements, analytics, or anything distracting. My motivation and payment is to see what kind of beautiful creations you come up with. If you build something nice, please send your HTML file to curator໑exophysics.net :)
If you do appreciate my work and would like to buy me the equivalent of a coffee, I invite you to check out my patreon page. I'm not starving, but any contributions are appreciated and will allow me to focus on more projects like these.