Ok, so this uses https://rapier.rs/ https://rapier.rs/ which is very cool Rapier, alongside https://nalgebra.org/ https://nalgebra.org/ (which it uses undernea

Ok, so this uses https://rapier.rs/ https://rapier.rs/ which is very cool Rapier, alongside https://nalgebra.org/ https://nalgebra.org/ (which it uses underneath) has seriously good documentation and some advanced features like cross-platform determinism (something made hard by the way floating point differs between platforms)