DREAMM is a pretty significant project, and differs from ScummVM in a few ways. Primarily, ScummVM is an engine rewrite. They write new code that copies the behaviour of the original games.

Aaron Giles worked at LucasArts and was instrumental in porting SCUMM to Windows (for Full Throttle and Curse of Monkey Island). DREAMM is a full x86 emulator that takes the original game code and runs it directly.[0]

Amusingly enough, I guess that makes DREAMM more of a virtual machine than ScummVM is.

[0]: https://aarongiles.com/dreamm/docs/v21/#faq-scummvm