Grumpy Gnome Software - Source code of games programmed for DOS using Allegro and DJGPP. - http://www.grumpygnome.8m.com
Map Editor - Mappy for PC (DOS and Win95)- A utility for creating flexible 'maps' for tile based 2D games (scrolling shoot-em-ups, or 8way scrolling adventures, whatever). - http://www.tilemap.co.uk/mappy.php
Allegro Games Depot - a list of games that are made or are being made with/for Allegro. - http://www.allegro.cc/