C# lib for processing font files - TTF (TrueType), others
See the question and my original answer on StackOverflowDon't know what you want to do exactly, but WPF has a cool GlyphTypeface Class that is quite abstract and quite independent.
This is how you can start with:
GlyphTypeface ttf = new GlyphTypeface(new Uri(@"c:\windows\fonts\verdana.ttf"));
There are also the GlyphRun Class and the GlyphRunDrawing Class.
Otherwise, if you're looking for the big picture, open-source, you can also check the FreeType Project, available here: http://freetype.org/