The SCUMM engine is one of the most famous engines used to create adventure games. It was used by LucasArts for all of their adventure games from Maniac Mansion to The Curse of Monkey Island, and in most of the Humongous Entertainment games until 2003. However, it's fame mostly comes from the popularity of the adventure game interpreter suite, ScummVM, which began in 2001 as a fan interpreter for the classic LucasArts adventures, and has since been expanded to include many other adventure games.
Since 2008, it has been possible to create fan games that actually use the SCUMM engine, specifically that used by Day of the Tentacle. Two fan games have been released so far, Open Quest using the SCUMM compiler ScummC, and Indiana Jones and the Call of Thunder, using the other SCUMM compiler, ScummGen. The Indiana Jones and the Call of Thunder source code has been extended to a completely playable game for this collection.
With the SCUMM Fan Game collection, you can now play both of these games on your Dreamcast. It's available to download now from the DC Evolution Sourceforge repository.