Task: Question Understanding
Input (English): Context : Dungeon Crawl Stone Soup is a free and open source roguelike computer game, which is the actively community-developed successor of the 1997 roguelike game Linley's Dungeon Crawl, originally programmed by Linley Henzell. 
Question : Which is the basis of Dungeon Crawl Stone Soup?
Output (English): based on