MATLAB

MathWorks MATLAB software is a high-level programming tool intended for scientific computing.

There is a large number of free and public MATLAB libraries.

Geoscience MATLAB programs and libraries
This list is taken from List of free geophysics software.

FLOSS and MATLAB
Strictly speaking, MATLAB code cannot be described as free, libre and open-source software, because it depends on the MATLAB suite of products, which are proprietary. So, for instance, it will never be certified as FLOSS by the Open Source Initiative or the Free Software Foundation. However, it is often free of charge and you can read the code, so you might regard it as open if you have ready access to MATLAB.

Even if you don't have MATLAB, most MATLAB code runs on GNU Octave, a FLOSS clone of MATLAB.

Other resources

 * MATLAB Recipes for Earth Sciences — Book by Martin Trauth