[sebastiansm]

R or the Python Scientific stack over SAS or SPSS.

[jimbokun]

Or MATLAB.

[jimbobthrowawy]

I think GNU Octave is the free software MATLAB alternative. Since it aims to be highly compatible and run the same code. Various python stacks do more things, and do them differently.

[sebastiansm]

I was going to write that software too, but still think that Matlab is so much superior, or maybe is the nostalgia from university years.

[MH15]

MATLAB is not open source, or even free.