VCS is a visual d20 3.5 combat program for dungeon masters. If you have dual monitors, one can show the DM map and the other the player's. It is possible to 'hide' things, and the players will only see what's in range or what they've seen before. After drawing the map, players can be moved, and over 850 standard monsters selected from for them to fight. Huge maps can be drawn and filled with monsters very quickly.
Erebus is a 2D real-time role-playing game. Though in its early stages, it is already playable with three quests. It is a classic point-n-click style RPG, with dungeons to explore, enemies to fight, NPCs to talk to, sub-quests to complete, scenery to interact with, weapons, treasure, and other items to find.