Beef is a flexible interpreter for the Brainfuck programming language.
It is not optimized for binary size or for execution speed: its goal is to be flexible enough to run most Brainfuck programs unmodified, and most importantly, to be confortable for the programmer. That said, Beef is also quite fast.
Features
Beef has no hard–coded size limits, which means it can run huge programs and provide them with a huge memory tape, if you have enough physical memory.
Its behaviour can be configured at runtime with command–line switches. These switches allow Beef to emulate other interpreters and to fit the programmer's habits and tastes.
It has been so far successfully compiled and run on GNU/Linux, GNU/Hurd, FreeBSD and Microsoft Windows. It is probably trivial to port it to other operating systems.