I'm not exactly sure. It's sometimes hard to tell what is the driving engine and in reality, both seem to feed off one another. In the early days, it was considered a badge of honor to provide a more elegant hack (same result - fewer instructions). We used assembly language to accomplish this...very fast but reasonably difficult because it was low level and programmer hostile. Programming language has become very high level which has resulted in a lot of very sloppy and inefficient coding, requiring much more memory.