Dungeon Mastery is a complete Dungeon Master’s aid. Not only does it allow you to create a complete fantasy setting, but was developed specifically to aid in the actual play of TSR's Advanced Dungeons & Dragons 2nd Edition fantasy role-playing game. Dungeon Mastery is $10 shareware - nuf said.
Dungeon Mastery is primarily composed of three stacks: Dungeon Mastery, DM Reference, and Module Maker. I've also included a fourth stack to be used as an alternate home stack when running Dungeon Mastery from floppies. This may be important to you, even if you have a external hard drive, since you may want Dungeon Mastery to be as portable as your Mac.
Stack 1) Dungeon Mastery—this stack allows the DM to create random encounter tables, interactively resolve combat, track experience, keep notes and also perform a variety of other tasks (roll dice, consult charts, determine treasure awards, translate between languages and track the passing of seasons).
Stack 2) DM Reference—this stack allows the DM to create and keep detailed data on characters, monsters, spells and equipment.
Stack 3) Module Maker—this stack allows you to create adventure modules. With it you can easily map out an area and create a custom adventure (you are encouraged to share any stacks that you create—I especially would like a copy!).