The Lisp programming language made REPLs (Read, Evaluate, Print, Loop) famous. REPLs are interactive programming environments where the programmer gets immediate feedback on lines of code they just typed. Today REPLs are common in Python, F#, and nearly every mainstream language. While using ChatGPT through the OpenAI website I noticed parallels to a REPL. Both setup ongoing dialogues between a user and their computer system. The concept of REPL and ChatGPT sessions is that a single idea or concept can be declared and then refined until it works. The key feature is that the context of the conversation is preserved within a session. For REPLs this means symbols, state, and functions. For ChatGPT, it’s the thread of discussion.