... arch-hacker James Gosling (designer of {NeWS}, {GOSMACS} and Java), to "...modify a program with no idea whatsoever how it works." (See {whacker}.) It is actually possible to do this in nontrivial circumstances if the change is small and well-defined and you are very good at {glark}ing things from context. As a trivial example, it is relatively easy to change all 'stderr' writes to 'stdout' writes in a piece ... — The Jargon File, Version 4.0.0