The Brainfuck Archive  
   Contains programs, compilers, interpreters, utilities, as sources and compiled versions.
   http://esoteric.sange.fi/brainfuck/

The Brainfuck Programming Language  
   Brief overview, introduction to commands, informal standards for programmers and implementers, and related resources.
   http://www.muppetlabs.com/~breadbox/bf/

Brainf***  
   Introduction to programming in BF; interpreters written in Brainfuck, C, Javascript; links.
   http://home.wxs.nl/~faase009/Ha_BF.html

Mr. Rock's Brainfuck Pages  
   Language introduction, tutorial, resources, BF to Perl converter.
   http://cydathria.com/bf/

Brainf*ck .Net Compiler  
   Brainfuck compiler that outputs .NET IL code. Includes source of sample programs.
   http://bluesorcerer.net/esoteric/bf.html

mod_bf  
   Apache webserver Brainfuck module; several BF code handlers. Easily make dynamic webpages in BF. Simple example of uses of Apache API, simpler than standard Apache mod_example. Descriptions, downloads, links. [Open Source, GPL]
   http://modbf.sourceforge.net/

Brainfuck interpreter in PHP  
   With a short tutorial and some examples to get you started.
   http://daniel.lorch.cc/projects/brainfuck/

Some Brainfuck Fluff  
   By Daniel B. Cristofani. Complete brainfuck reference; sources for various programs, including a Universal Turing Machine; brainfuck to SPARC compiler, and interpreters in C and JavaScript; suggestions, contest results.
   http://www.hevanet.com/cristofd/brainfuck/

Chaos Computer Club Cologne: Brainfuck  
   Descriptions (language, theory), code samples, original software (compilers, assembler, interpreter), mail list, links. Working to implement BF in hardware. English, Deutsch.
   http://koeln.ccc.de/prozesse/zombies/brainfuck/index.en.xml

BF Debugger Project  
   An integrated GUI debugger for the development of software using the brainf*** programming language.
   http://bfdebug.sourceforge.net/

The Esoteric Non-existent Standards Institute  
   The "non-existant" standard's body for Brainfuck. Contains some efforts to provide formal language specifications for the language and other resources.
   http://esoteric.sange.fi/ENSI/

Brainfuck.ca  
   GPLed Brainfuck interpreters and source code converters.
   http://www.brainfuck.ca/

GBrainfuck  
   A small, efficient, GPL'ed Brainfuck language interpreter written in C and intended to run on *NIX machines. [Open source, GPL]
   http://gbf.sourceforge.net/

BrainScript  
   An Active Script implementation of Brainf*ck.
   http://brainscript.sourceforge.net/

Urban Müller  
   The "father" of Brainfuck. Although this doesn't list anything for the language, it can give you an idea of who would come up with this language.
   http://ftp.wustl.edu/~umueller/

Brainfuck programming with Brainf+++  
   A Brief tutorial of the language.
   http://brainfuck.kicks-ass.net