OO is pretty conceptual without something to back it up.  In this case, Smalltalk.<p>GUI&#x27;s... I think that was not him, or certainly not just him.<p><a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;The_Mother_of_All_Demos" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;The_Mother_of_All_Demos</a>