- Import is a within-process method of code re-use. - Exec is a between-process method of code re-use. - The import method of sharing code does not work between processes, except via `fork()`, and because [[Concurrency Primitives are Broken]], `fork()` "can't" be mixed with threads. - The import method of sharing code does not work between languages, except via awkward foreign function interface APIs. - Tl;dr: Unix got it right. Reject modernity. Embrace tradition. --- Todo: Explain exec vs import and the intermediate level abstraction of all programming languages. Todo: The Babel puzzle belongs here.