I use flymake in Emacs to check code written in several languages. However, I can't see any way to use flymake on elisp itself.
I'm aware of elint-current-buffer, and byte-compile-file, which both give useful warnings about undefined variables etc. Oddly, they don't always give the same errors: for example, elint doesn't warn about (require 'cl). I've also tried auto-compile-mode (available on MELPA) but this still writes the warnings to a separate buffer.
I would really like my elisp code to be underlined when I make mistakes, as I type. How do I do this? I've configured flymake before, but that was with external programs, not Emacs itself.
The Emacs wiki has this to say about flymake for emacs lisp, though it doesn't seem very complete.
flycheck supports Emacs Lisp "out of the box", though.