Gary McGraw was the first doctoral candidate to work on the Letter Spirit project:

https://web.archive.org/web/20220331021500/http://goosie.cog...

And John Rehling did a second portion in his doctoral work:

https://web.archive.org/web/20150320160815/https://www.cogsc...

(Thanks for this complaint - I hadn't realized that Rehling's thesis was linked from the Waybacked version of his personal page, and that finally completes my collection!)

You can also read Chapter 10 in Hofstadter's 1995 book "Fluid Concepts and Creative Analogies" for a pretty solid overview.

But yeah, seeing this project immediately reminded me of Letter Spirit, since it's basically a web editor for gridfonts.