[adamgordonbell]

Ah, I did not know that. My bad. Maybe he was more of a popularizer of the approach then?

[martinky24]

Even at Wolfram Research, Theodore Gray is credited with inventing/developting THEIR initial interpretation of the notebook interface. His Wikipedia page [1] makes that clear.

1: https://en.wikipedia.org/wiki/Theodore_Gray

[justin66]

I'd guess MathCAD was quite a bit more popular than Mathematica in the nineties, given Mathematica was something like ten times as expensive.

[bachmeier]

I certainly won't blame anyone for saying that, given that it's repeated so often that it's turning into common knowledge.