What makes a programming language fast?

One factor is time spent on optimizing the compiler or interpreter. In addition to having its own free Python distribution, Intel produces C++ and Fortran compilers. Although it charges for those compilers, I think the main reason it has created them, even though gcc exists, is to increase peformance on its hardware.

- Whether it is compiled or interpreted

- How abstract it is / what 'advanced' features it provides

- The compiler