Irrlicht’s new font tool is my attempt to solve the problems with the old font system. It only supported ASCII characters, couldn’t span more than one texture, was Windows only and could only be compiled with a commercial Microsoft compiler with a resource compiler, it didn’t support antialiasing either.
The new font tool writes XML files and uses Irrlicht for rendering. Although it was first Windows only, it was modular and a Linux generator was later donated by Neil Burlock, it does not yet support OSX/Cocoa font generation. Because the new fonts are based on sprite banks, it should be possible to remove characters and reorder them in future, even supporting animated letters if you’re into that sort of thing!
I also made a tessellator for vector fonts, but this used the brute force and ignorance method and is still incomplete, it saves but lacks a loader. The font tool has been part of the Irrlicht distribution for a long time now, you can get it along with the source from the main website.