FudgeFont is an addon for Allegro 4 which allows reading .ttf files (by using libfreetype) and use them with Allegro's normal font routines. This works by internally converting the TTF font into a bitmap font. It has full unicode.
Note that Allegro 5 has builtin TTF support and so for new projects you should not use FudgeFont but instead the newer Allegro version.
Sourceforge Project Page