Back in the day I got sent on a Lisa software development course/conference - in Bolton (UK) of all places.
I can't remember if it was an official 'WWDC' thing - but various Apple bigwigs were there - including John Sculley I seem to recall.
Software for it - including much of the operating system - was written in a dialect of Object Pascal. I felt that the GUI, Mouse etc. were all a bit clunky, slow and 'pointless'. The thing that amazed me at the time was the ProFile 'Winchester' hard disk - 5Mb seemed almost infinte at the time!