[madenine]

R and Python are not your only options. Check out the article for some other languages people are using.

R and Python are probably the two with the most support/community materials around them - lots of tutorials, libraries, guides etc.

[jsemrau]

Which is the one main reason why PHP is still around. If you are starting a new language or a new project, it is better to have examples and guides available.

I am preferring python to "R" because it gives me better search results.