I aim to categorize and rank software based on their main application.
Now I think you're right about R (it's mainly a statistical software) but what about Python (programming language) and octave (which runs in Linux OS that isn't a prevalent OS here at all)?
Python (spyder plus anaconda2) will run fine on windows (that's how I use it) and so will octave. In the recent past, python has been growing very fast. Matlab not so much (since its expensive) and octave even less. Some people also use julia and mathematica