Measuring optical sizes
For the last year or so, Yanone has been working on a very interesting tool called Fontquant. The aim of the tool has been to help to quantify the technical quality of the font. It can tell you whether superior and inferior numerals are present; it can tell you which glyphs have small-caps. It determines information about the font’s appearance: it works out that Open Sans has a double-story g, that Farro’s numerals are proportional lining by default.