For Emacs Lisp users M-x macrostep-expand from the macrostep package is a cool tool that allows for inline expansion/collapse of macros, step by step if there a

For Emacs Lisp users M-x macrostep-expand from the macrostep package is a cool tool that allows for inline expansion/collapse of macros, step by step if there are multiple levels of macros. There is also M-x pp-macroexpand-last-sexp that comes with Emacs. And the macroexpand function itself of course.