Hugo is a system for developing and playing sophisticated computer adventure games (or “interactive fiction”).
The complete system comprises a high-level programming language, world-simulation library, compiler, runtime engine, debugger, and other tools. Games can be designed for player input keyboard and/or mouse in addition to using Hugo’s full-sentence natural-language parsing capabilities, and can make extensive use of graphics, sound, music, and video playback. Hugo is powerful and versatile enough to have been used not only for games such as Future Boy!, but also for presentations and tutorials, prototyping, and other applications. Hugo’s cross-platform support is broad, including official implementations for Windows, Macintosh, Linux/Unix, Windows Mobile/Pocket PC, and Palm, with additional versions available for other platforms. The source code for all components is available.
Here is a game made with Hugo: Cryptozookeeper