The Dark Times is a Star Wars Battlefront II mod with a heavy single-player focus. It adds many new features to the game, including (but not limited to!) wave modes, randomized units, heroes, and skyboxes, and AI hero support. Its sequel, Rising Son, adds more of the above as well as several new maps and scripted missions.
This mod rocks!!! Space Mon Calimari is the best custom mission I've ever seen!