I can't reply to the guy saying julia is the only one. But there are others.

Ceres uses dual numbers

https://github.com/ceres-solver/ceres-solver/blob/master/inc...

This library from google is used everywhere in robotics, so it's hardly some backwater little side project.

So does c++ autodiff https://github.com/autodiff/autodiff/blob/main/autodiff/forw...

So does Eigen: https://eigen.tuxfamily.org/dox/unsupported/AutoDiffScalar_8...