Is teaching people data structures and programming techniques in C really useful today? Yes I know C is used in many things still and in Linux. But there is far more variety in what people are paying programmers to use these days, most of them OO or Functional in nature, neither of which C is. Maybe there is no other common denominator language one could use that is more generally applicable? If you ignore Objective-C I haven't used plain C for anything at all since 1999 even though I used it for more than a decade from the mid 80's on as my only language.