See it's entry on gopherpedia:
So, befunge exist - more or less - in two flavors:
In the last years I wrote my own implementation of an funge-machine in Common Lisp:
It passes als Mycology[1] tests and some fingerprints are implemented.
A bit more interesting is my befunge-IDE:
It allows to edit and watch code running in 1 to n dimensional funges.
Watching funge code is like having a transparent clock.
(btw, you'll also need my OOP approach to use ncurses, cl-tui)
tui - a common lisp framework for OOP style ncurses
The code is unfortunately bitrotten and just partly documented, as I haven't touched it in the last ~5 years. But any suggestions are very welcome.
Footnotes: