lengyel told me he has implemented some sort of hinting on the gpu for slug (i suspect it's not programmable, but didn't ask)
> kerning, ligature replacement, combining diacritical mark placement, and character composition. Slug also supports a number of OpenType features that include stylistic alternates, small caps, oldstyle figures, subscripts, superscripts, case-sensitive punctuation, and fractions.
Probably still uses the CPU.