Development

Game Boy - http://shen.mansell.tripod.com/games/gameboy/gameboy.html
Source code and utilities.

Game Boy Developer's Kit - http://gbdk.sourceforge.net/
Software toolkit.

GameBoy Files - http://www.personal.triticom.com/~erm/GameBoy/
Source code and tools.

GameBoy Guts - http://uk.geocities.com/gameboycartsuk/index.html
Photos of contents of cartridges.

Gameboy Terminal Server - http://gbts.sourceforge.net/
Tool for display usage.

GB Assembler Studio - http://web.telia.com/~u31802901/nicbit/gameboy.htm
Tool for fast development.

GBBG Game Boy Beyond Games - http://d.webring.com/hub?ring=gbbggameboybeyon
A web ring for development of non game applications.

Harry Mulder's Gameboy Development - http://www.devrs.com/gb/hmgd/intro.html
Code and tools for assistance.

Jeff Frohwein's GameBoy Technical Page - http://www.devrs.com/
Tools and information on development.

Ken's Gameboy and PIC Projects Page - http://www.geocities.com/kkaarvik/gameboy.html
Utilities and projects.

Little Sound Dj - http://www.littlesounddj.com/
Game Boy music program containing a sequencer enabling waveform editing or a hardware synthesizer.

Marat Fayzullin's GameBoy Page - http://fms.komkon.org/GameBoy/
Development tools along with game and technical information.

MBC5/CPLD for the Gameboy - http://home1.stofanet.dk/hvaba/gameboy/mbc5cpld/index.html
MBC5 controller for Xilinx cpld.

MQP Game Boy Project - http://www.mqp.com/fun/gb.htm
Program and information allowing classic books to be read on Game Boy.

Programmer-Net - http://www.enliten.force9.co.uk/
Game Boy Programming information and crib sheets.

Rednex Gameboy Development System - http://www.otakunozoku.com/Articles/Development/RGBDS/RGBDS.html
Tool to help with programming.

Reiner Ziegler's Website - http://www.reinerziegler.de/
Information and ReadPlus software for programming original Game Boy carts.

SkyRank Games - http://www.skyrank.com
A development team consisting of Pocket PC, GameBoy Color and Advance programmers, musicians and artists. Their goal is to design commercial quality games.

TeamKNOx - http://members.tripod.com/~TeamKNOX/
Hardware side of Game Boy emulation and development.

The Blue Hippo's Paradise - http://bluehippo.freeservers.com/
Various cropping and RAM utilities.

The Fountain Of Decay - http://members.lycos.co.uk/GBCE/
Code editor and source code.

The GameBoy Development Ring - http://d.webring.com/hub?ring=gameboydev
Webring for developers and sites about developing.

The Open GameBoy Game Project - http://opengbgames.sourceforge.net/
Open source games.

WLA DX - http://www.hut.fi/~vhelin/wla.html
Macro assembler for the handheld.