Sql is extremely popular, that's the LAMP stack. Rails and Django led people astray for a while but that's ending.

Prolog should be more popular, it should be at least embedded in every program, even in the browser.

If there are more than a few for loops or if else statements than the majority of the program should be encoded in sql/prolog.

If you look at all these javascript frameworks, the core concept they're missing is relational programming. The program should be a loop that takes all input events like mouse clicks, etc. and then queries a prolog engine about to what actions to take.

It's getting more popular steadily. Map/reduce is being replaced/complemented with distributed sql, and the frontend will also come around as people starting embedding prolog into their guis (LAMP stack in the browser).