Cocoa Text System

The Cocoa Text System is an object-oriented framework provided by Apple to provide text services to applications developed under the Cocoa API.

History
The Cocoa Text System originated as NSText in NeXTSTEP, which evolved into Mac OS X. It then functioned in parallel with the ATSUI framework, which was superseded by Core Text with the release of Mac OS X 10.5 "Leopard" in October 2007.