Here is one of my most favorite MATLAB-based earth science toolboxes: the TopoToolbox by Wolfgang Schwanghart. TopoToolbox is a program for the analysis of digital elevation models (DEMs). It’s free and open source (as long as you have MATLAB).
First released in 2010, it quickly became one of the most popular and widely used MATLAB toolboxes in earth sciences. The toolbox is continually expanded and current topics and applications are discussed in a beautiful blog.
Schwanghart, W., Scherler, D. (2014): TopoToolbox 2 – MATLAB-based software for topographic analysis and modeling in Earth surface sciences. Earth Surface Dynamics, 2, 1-7. [DOI: 10.5194/esurf-2-1-2014, Discussion paper: 10.5194/esurfd-1-261-2013]. open access and software available here [DOI: 10.1594/IEDA/100175].
Schwanghart, W., Kuhn, N. J. (2010): TopoToolbox: a set of Matlab functions for topographic analysis. Environmental Modelling & Software, 25, 770-781. [DOI: 10.1016/j.envsoft.2009.12.002]
Schwanghart, W. (2010): Ein numerischer Werkzeugkasten für die Reliefanalyse. Geosciences Actuel, 4, 16-18. [pdf]