Languages like matlab, R and Python (via numpy), let you do efficient computations as long as you can let them happen in the core, that is written in C and Fortran. This is very often possible, but in some cases you find that it is not, and then it will either be very slow or you need to write a C module for it. None of these languages is designed to make it easy to make a compiler/runtime that is from the ground up efficient. They are instead a rather inefficient interpreter with a really good library. This is where Julia differ. It is designed exactly to be efficient from the ground up.ground up.