> That just leaves the PARC-influenced "object-oriented" element which later showed up on the NeXT in the form of Objective C and the NeXT APIs. Had Big Mac's software already taken some steps in this kind of direction? Or was it an ambition for later, or simply not on the roadmap at all yet? I have no idea.

This was already present on the classical Macs, and Lisa, via the Object Pascal frameworks, and later evolved into its C++ replacement.

Copland was also heavily C++ based.