Your comment hits the nail on its head! These languages are still used in deep engineering space, nuclear & defence companies and institutions like NASA and the US Airforce. I like what your project is doing. How does the analytical testing works? can I create write my own tests?

Each test is responsible for a part of the UMAT subroutine, checks it's correctness, compares the subroutine (FEA) with the analytical. Plot their results and show whether the tests passes or fails. AI is built into the process too, but in a manner where they are deterministic and with strong grounding on the physics.

You can also write your own tests in Fortran and run it. You can also share it to the community for others to use.

You can read the docs https://jacobee.netlify.app/docs