Cat's Eye Technologies' Befunge-93 - The official web site for the Befunge-93 programming language; maintained by Chris Pressey, the creator of Befunge.
VSync's Funge Stuff - Features a portable Befunge-93 pseudocompiler and several other compilers and interpreters. Demonstrates how to use Befunge as a CGI scripting language.
Tim's Befunge Compiler - This "pseudo-compiler" will create an ANSI C program from a Befunge-93 source file. Programs can still be self-modifying even after they are compiled.
ZBefunge - A Befunge-93 interpreter written in Inform, and runnable on just about anything.
Wikipedia Articles
Befunge - Befunge is a stack-based, reflective, esoteric programming language. It differs from conventional languages in that programs are arranged on a two-dimensional grid.