In fact Knuth wrote a wonderful article explaining the idea. The article is available online, and is just an explanation but a superb performance — “The Concept

In fact Knuth wrote a wonderful article explaining the idea. The article is available online, and is just an explanation but a superb performance — “The Concept of a Meta-Font”, by Donald E. Knuth, in Visible Language, XVI 1 (Winter 1982): https://s3-us-west-2.amazonaws.com/visiblelanguage/pdf/16.1/the-concept-of-a-meta-font.pdf https://s3-us-west-2.amazonaws.com/visiblelanguage/pdf/16.1/... (Republished in the book/collection Digital Typography.) So he seems to have invented the idea, at least as far as computers go.