Here's something that's always bothered me. In the HPC and scientific computing world, it seems that the word 'program' is never used to refer to what is being

Here's something that's always bothered me. In the HPC and scientific computing world, it seems that the word 'program' is never used to refer to what is being run on the computers, rather it is always 'codes' (note plural) that are executed. Does anyone know when or why this split of terminology occurred?