I'm schocked that I had to read this far down to find Hypercard. It is such a highly regarded piece of software, though I sadly never had the opportunity to use it myself. I can't help but wonder what it might have turned into had it been open sourced, made cross platform, and allowed to flourish.

And while I'm here, WordPerfect 4.2. That program was a high water mark in word processing for me. What I wouldn't give to hit Alt-F3 in Word to Reveal Codes [0].

[0] https://mltshp.com/p/1EL4C