Octave

Octave is a GNU implementation and extension of the programming language used by MATLAB.

I happen to like Graphic User Interfaces for programming languages.  If you do too and you are using Windows you might want to look at DomainMath IDE. 

DomainMath IDE is a set of java scripts so you will need to install the Java Runtime Environment.

Octave seems to use memory differently than Python.  Unless you want to learn the MATLAB language or have a specific need you might want to use Python.  I'm slowly learning both so cannot make emphatic claims about either.  The SciPy modules in Python add a lot of array handling features.  I haven't seen anything I can do in Octave I cannot do in Python but I have encountered limits in Octave I've blown past in Python.

While everything I can do in Octave I can do in Python, after working on the problems in "Computation Neuroscience" I see some things are easier to code in MatLab.