I've added support for true-type fonts using stb_truetype, a minimalistic public domain library written by Sean Barrett. While working it's still an early implementation so some polish still needs to be done. The code for loading and raster glyphs is really small and simple. However, as you can see the anti-aliasing doesn't look very good. Could be a problem on my side so I'm gonna look into it sometime. I've a also done a fairly sophisticated font cache where glyphs are more or less optimally packed when needed.
On the subject of public domain libraries I can also recommend stb_image for loading bmp, tga, png, jpeg without zlib and stb_vorbis for ogg vorbis.