[userbinator]

I think this is a question of interface vs. implementation.

Python, JavaScript, and other languages which are traditionally considered interpreted but may do (JIT) compilation in their implementation are used as if they were interpreters: to the user, there's no separate compilation step. You run python somefile.py or node somefile.js (or refresh a browser holding a page), and editing the source code causes the next invocation to take those changes immediately. Contrast this with C/C++ and Java where there is definitely an explicit compilation step in nearly all implementations.

The program in this article thus is an implementation of a compiler, but has the interface of an interpreter.