REPL

REPL = Read–Eval–Print Loop.

Amounts to mean 'takes user input, shows you the result'

Historically this typically meant 'iteractive CLI, on a shell', or maybe embedded in something (like emacs).

The term seems loosely associated with LISP, and seems to sometimes be used to evoke that functional-programming association.

The concept also seems to have recently been widened to "absolutely anything interactive that is at least one step easier than manual busywork", apparently including

• text mode shell, as before

• a component you write

e.g. live formatting of markup from a text field

• web-editable client-only demo code thing - like jsFiddle/codepen/replit/similar, but often a variant specific to the context you named it in - so it's

not very clear whether it's evaluated in-client or via server API

not very clear whether it's whether it means interraction on-webpage, or in a console

not very clear whether it's transient, or saveable

not very clear whether it's collaborative

not very clear whether it's compiled or not - there are things described as REPL that do "take this code for a compiled language, compile it server-side, run it server-side, send me the result".

not very clear whether it actually means "a completely online IDE"