If you haven't seen it, the Interface Builder got its inspiration from this Interface Builder written in Lisp: https://vimeo.com/62618532 The version in the video actually ran on a TI MicroExplorer Lisp Machine NuBus board in a Mac. There were other ports which ran directly on the Mac in Lisp.
The thing was shown to Steve Jobs and he hired its main developer, Jean-Marie Hulot.
Ah yes, I remember the funny guy facing various dramatic software difficulties in the first part of the video.
This builder does look like a precursor to NeXT's and HyperCard too. I like that the "toolbox" appears next to the mouse, instead of having to go to the top menu or sidebar to select a new tool and back to position to use it. I missed that it ran on a Lisp processor, very cool!
And that the main developer later worked at NeXT and Apple.
> Jean-Marie Hullot authored important programs for the original Macintosh, NeXTSTEP and Mac OS X platforms. These include SOS Interface for the Mac, which later became Interface Builder for NeXTSTEP (1985), and later still evolved into an important part of Mac OS X.
> He also came up with the idea of the iPhone and led the iCal and iSync development teams for Mac OS X (2002).
..Searching for "SOS Interface for the Mac", I guess it's Sophisticated Operating System, "the primary operating system of the Apple III computer" released in 1980.
The thing was shown to Steve Jobs and he hired its main developer, Jean-Marie Hulot.