I'm trying to make sense of what we have in the fonts directory…
We have "ahem3.ttf" in fonts/, and an "AHEM____.TTF" in fonts/ahem/.
Both of these fonts claim to be "Ahem" in the "Ahem" family, so only one can be installed/active at a time. ahem3.ttf seems to have a higher version number, and a few more characters.
I presume ahem3.ttf is required by some tests (as why else add the extra characters?): it was added in 2010 by Aaron Eicholz in an absolute massive commit. Should we just drop the old AHEM____.ttf?
The other files within fonts/ahem/ appear to be a Postscript copy of the AHEM____.TTF, and a (Classic Mac) Font Suitcase that has been *.sit compressed (probably because it relies on resource forks to get preserved). Given I don't think anyone is likely to run tests on a platform that doesn't support TrueType fonts, we should likely just drop them—so all we have to do is work out which of the two Ahem copies we should be keeping!
We might want to also add a LICENSE file or two for the sake of clarity around the fonts: fonts/ahem/ contains a COPYING (contrary to the naming used everywhere else in the repo!) declaring it to be CC0; fonts/ahem3.ttf contains metadata within the file declaring it to be CC0; the fonts in fonts/ahem-extra/, however, make no such comment—they appear to be based on fonts/ahem/AHEM____.TTF, but given they make no further comment, I presume the LICENSE at the top of the repo applies (FWIW, they appear to originate in the massive MS 2.1 dump, in case anyone from MS knows whether the license change from the original was deliberate).