>>"Precisely. The whole "my language is better" argument is completely void." You say later that the difference is "only on how you will do it". If you stop to

>>"Precisely. The whole "my language is better" argument is completely void." You say later that the difference is "only on how you will do it". If you stop to think for a second, you come to realise that syntax, abstractions and the big elephant in the room: how "tuned" a language is for the myriad of computing platforms/operating systems/domains (scientific, business, web) -among many other factors- play a HUGE part in how you can develop software and how performant it can/will be. So languages does matter. >>"Note that there is no theoretical bound preventing an Haskell compiler to generate code equally fast than the one of a C compiler for any program." But it won't, because at the end of the day, a machine has to execute the programs written in a language and C was designed for a machine with certain characteristics in mind while Haskell/Lisp and other higher level languages are an exploration in abstractions. When Abelson & Sussman says: "Programs must be written for people to read, and only incidentally for machines to execute.", there is an implicit understanding that trade-offs are being made and its not the same as C and other lower level programming languages. Until a machine appears that isn't limited by the constrains of the present, making trade-offs is inevitable and that too, does matter. @jacquesm: Great write-up. Enjoyed every line of it. P.S: I make no distinction between a language and its implementation here.