In the long run, three players can remain standing:
- The obvious choice - it's (currently) JavaScript, because some of us will always follow highlander rules. It used to be PHP, when JavaScript wasn't popular yet, at the dawn of time. Before that it was Perl because CGI. Python and Java arguably each had a moment sometime between Perl and JavaScript.
- Whatever is fastest for high performance - odds favor golang, but I'm just guessing. Could honestly still go to C. Many languages have died before unseating C in high speed contexts.
- Whatever has the best library support. - In my random opinion, there's currently a run-off between Python and NodeJs to unseat PHP and Java.