Unlike a real iceberg, however, the tip in this case makes up the bulk of the ice. There are many languages available, each with its cadre of adherents. There is also a healthy market for components for the major languages. Some of these toolkits are almost minilanguages in themselves. Which language you choose to use is often a function of what you have to do.
Some programs naturally lend themselves to certain languages.
No one has quite done it yet, but the line between those categories is fading. Your employer or an existing code base will dictate it for you. Still, it is good to have a perspective of what's out there and what you could be using. If you want to know what language will help you land a new job, that's easy. The answer is all of them.