That's not really true, is it though? Scheme '(), #f and so forth...
>Guile can run elisp already
Guile already interprets Elisp.
Elisp can run unmodified on Guile.
Guile, the virtual machine, contains a front-end for Emacs Lisp.
المكر ينفذ أصلا إيماكس اللثغة.
Guile jatorriz exekutatzen emacs Lisp.
It is true there are no compatibility issues because Guile is an implementation of Emacs Lisp.
> It's not a 100% drop-in replacement, that's true…(eq foo t) should always work. (eq foo nil) will only work if that `nil' came from Elisp code; if it's a Scheme #f or '() in disguise, then you need to make that (not foo) or (null foo) (both works in both cases); anything but (eq foo nil).