Copland

Copland was the codename for an unreleased Mac OS-based operating system that was intended to be the modernized successor to Mac OS 7. The Copland project would start in March 1994 and eventually be cancelled in August 1996. This version would aim to port a majority of the Mac OS features to a nanokernel in an attempt to increase kernel stability and improve multitasking functions while retaining compatibility with the classic Mac OS applications.

Following the cancellation of Copland, most of the Finder and shell features that could be ported from Copland would be implemented in Mac OS 8. Apple would seek a new operating system to continue where Copland was left off, and after the acquisition of NeXTSTEP, would build from that foundation to start a new generation of Mac operating systems known as Mac OS X.

Currently, only three builds of Copland have been found, and no emulators are known to boot any of them.