Font drawing algorithms are extremely complex because they have to decide which pixels to highlight based on the mathematical equations inside the .ttf file. When you need text in big sizes like 48 or 60, one or two pixels these algorithms “forget” to highlight doesn’t make much difference, but when you need text at size 8pt or 11px, each pixel counts. And these use to be the text size for KDE and Gnome widgets, text for web browsing, and almost everything else we see on the screen.
To solve this problem more efficiently, beside of the mathematical equations inside a .ttf file, a font designer (a human being with a font creation software) also put some extra information to help the font renderer make correct decisions for this small size text. This process is called grid-fitting or hinting.http://www.blogger.com/img/gl.link.gif
The point is: the technologies to interpret this hinting information are patented by Apple, and they are commonly called True Type Byte Code Interpreters (or simply BCI)
With reverse engineering, the Freetype Project has implemented a byte code interpreter, but due to legal issues in some countries, some Linux distributions, like SUSE disable it at compilation and packaging time.
