Nazghul is a game engine modeled after the late-1980's game Ultima 5 (aka u5) by Origin Systems (no affiliation with Origin or its parent company is implied by that statement). The goal is to do everything u5 can do, except for the bad parts, and to do some things better.
Nazghul presents a very similar user interface and game system as u5. The main view is top-down and tile-based. Players control a party of one or more characters. The principle game activities are exploration, turn-based combat with hostile npc parties, solving puzzles and experimenting with magic and artifacts.