If you want a list of heterogenous "things" you either a list of "I don't care about what's on list" and then it should work without much in languages like Haskell, ML and the rest or you actually have list of things with a common property, such as "I want to be able to turn these things into strings and sum them" or "These are either numbers or strings" -- all functional languages work well with the latter through ADTs and the first one can be solved easily in Haskell with existential types (I don't know about other languages)