Phet: Interactive Simulators for Science and Math

[nateb2022]

https://phet.colorado.edu/en/

[Georgelemental]

Many of the simulations on this site are Java web applets, kept running thanks to CheerpJ (https://leaningtech.com/cheerpj/).

[nanaian → Georgelemental]

CheerpJ developer here! If anyone has any questions about how the integration works, feel free to ask :)

[loa_in_]

It's absolutely positively amazing that playgrounds like this are available on demand with little prerequisites. The future looks promising.