The Center for Research on Concepts and Cognition
Letter Spirit is a project to make a program capable of inferring the style of some letters in a font (actually, gridletters in a gridfont, on a digital grid, like a digital clock) and then completing the rest of the font in that style. The first work was done by Gary McGraw on an Examiner capable of simply recognizing letters in the first place; the first mostly complete Letter Spirit was written by John Rehling. Our online papers include some old papers by McGraw et al. on the project, including McGraw's thesis; John Rehling's thesis naturally is the most complete description of his project.
Rehling's website includes the grid, sample fonts, the code, and his thesis.