At that stage, the name for Cocoa was YellowBox, and the Classic environment was called BlueBox IIRC. Apple also had a version of the Rhapsody frameworks that ran in NT, which they inherited from NeXT.
Rhapsody was the name of the OS developed under the leadership of Gil Amelio, it was heavily based on OpenStep (moreso than OS X), hence it's cross platform capabilities. There have been numerous aborted attempts at creating a next generation Mac OS under a variety of strange code names like Pink, Taligent and Copland.
