Windows Odyssey

Odyssey was the codename for a cancelled version of Microsoft Windows, which was scheduled for release in the fourth fiscal quarter of 2001, following Windows 2000. It was worked on alongside Windows Neptune, which was at first going to be the first consumer-based Windows operating system based on the Windows NT architecture. However, both Odyssey and Neptune were combined to create Windows Whistler, which eventually became known as Windows XP.

As of 2020, there are no confirmed builds under the name of Windows Odyssey.

Trivia
If a build of Odyssey was to surface, modern applications running on it might mistake the build for Windows Vista, as Odyssey apparently used NT version 6.0, which is the same NT version Windows Vista used.