How did you do your search? Some categories are listed together hense repeated. For example: JavaScript is almost always mentioned if the listing has anything to do with web development.

To me this means JavaScript is not a "language" in high demand but rather something that is expected by default. IOW, if you don't know JavaScript, you have no business applying for any web development position regardless of your primary tool. Kind of like an employer saying "I need a web developer and it would be nice if you know HTML." ?!? Huh?