HexRogue
A Java-based roguelike in a hexagonal format; established with alternating playable/unplayable spaces. A very simple, straight-forward version of Rogue, perfect as a coffeebreak roguelike, or introduction to the concept. Owner's site also has a Java version of classic Rogue, too.
It features a variety of room types and layouts and other alterations, as well. For example, a "hallway" layout with a horizontal, centered passage that has 10-12 rooms that connect not only through it's endpoints, but also through mainly N/S passageways that all connect with the main hallway; or a 4x5 set of tinier rooms connected with more numerous passages. Passageways also connect nonadjacent rooms.
Since it's walls are contained in unplayable spaces, "maze rooms" are generally fully-fledged rooms and not just scores of passageways, and some things like adjoining rooms appear as well.
M34T 03:17, 22 August 2008 (CEST) (original more detailed document lost)