Ask HN: What are all the FOSS programs for various mathematical explorations?

Basically, what are all the FOSS alternatives to things like Matlab and Mathematica? Solvers, visualizers, or anything having to do with computational math. I'm aware of Sage Math, Julia, R, Octave, Numpy, Scipy, and several more I'm forgetting atm, but am pretty sure there are many more. What are they?

https://www.sagemath.org/

https://juliastats.org/

https://www.r-project.org/

https://www.gnu.org/software/octave/

https://numpy.org/

https://www.scipy.org/

...