IELM is the Emacs Lisp REPL. It lets you evaluate any Elisp expression, prints the output and keeps track of previous commands. While it is a serious step-up from the humble eval-expression, it can be uncomfortable on several aspects. Let us improve it. Adding Eldoc hints Eldoc is a generic module used to display realtime documentation hints while you type. For Emacs Lisp, it means displaying docstrings when your cursor is over a symbol or when you start writing a function call.