Apple Advanced Typography

Apple Advanced Typography (AAT ) is a software- implemented comprehensive approach to clustering of font technologies of the operating system Mac OS X from Apple that combines several sub-concepts of recent developments in it, so it provides sophisticated typographic possibilities on the application level. In AAT are the options for dealing with fonts, as they existed under QuickDraw GX, picked up again after QuickDraw GX was hired by Apple. AAT enables automatic ligatures, different glyphs for each letter as well as automatic jewelry letters. AAT is, in many typographical features of the possibilities of OpenType.

Programs that support the AAT, are XeTeX, TextEdit and many other Cocoa applications.