content: cobol   Might be the best investment in the list actually,  if what you want is a means to making a good living without too much worries about competing against the cool kids fresh off fancy CS programs or the latest batch of H1Bs.... Seriously,  that’s the only one out of the list that can give you some kind of job security...  That said it all depends on what is your goal — learning to code as a cool hobby and a way to exercise your neurones,  or as a way to make a living... (for the keen hobbyists I would have added Forth or even PostScript — yep, you can program in ps,  and it’s good fun — to the list...) The list has some odd entries (CSS really?),  a lot of redundant entries (all the C derived procedural languages), some interesting entries (R is rarely taught in CS classes, yet used a lot in some fields), including languages I have never come across (wth is Julia?) Not a bad article IMHO — again if you are a hobbyist, learning oddballs programming languages can be fun,  it makes you discover very different ways of thinking about code (e.g., procedural vs functional languages)  What would be ‘useful’ languages to learn to land a more mainstream job would be a different piece altogether — another nice article would be what to learn to land a more off the beaten track job (that’s where cobol, fortran or R could be discussed in more details)