Campaign Cartographer - Campaign Cartographer is the leading map making software for games (RPGs, miniatures and wargaming).
Roll20 - Roll20 is a suite of easy-to-use digital tools that expand pen-and-paper gameplay.
Fractal Mapper - With Fractal Mapper, creating worlds has never been so easy!
Fantasy Grounds - Fantasy Grounds is a virtual tabletop to help facilitate play of tabletop-style role-playing games...
Dungeon Tile Mapper - Dungeon Tile Mapper is a web based tile mapping tool that includes many official D&D tile sets.
Astral Tabletop - Create, host, and manage your tabletop role-playing games — online or in person