I wrote parenface.el as an experiment in "hiding" parenthesis in lisp code. It is often said that lisp programmers simply don't notice the parenthesis (it's my experience that this is true) and it was once suggested in comp.lang.lisp that you could use an editor to colour the parens so that they are almost invisible and a lisp programmer wouldn't notice.

Boris Schaefer provided the main part of the code in a post to comp.lang.scheme and I tidied it up and "packaged" it.

PLEASE NOTE: I'm deprecating this code in favour of the much nicer paren-face.el by @tarsius.