I recently watched a talk by Bret Victor titled “Inventing on Principle”, where he explains his principle for inventing and subsequently encourages the audience to find theirs. His principle is that creators should have an immediate connection with what they are creating. This is a major problem especially in software development where the author of a program will need to change a bit of code and rerun it to see the effects.

Bret gave fantastic demonstrations on how much better graphics programming can be with instant feedback, and he even created a way to give instant feedback when writing algorithmic code. It’s at this point I had a realization about the popularity of REPL driven development.

REPL driven development is simply a way to get instant feedback while programming. As such, I do not think this development style should only be available in Lisp-like languages (such as Clojure). Or more generally, all languages can benefit from having instant feedback if only the tools existed for them.