The GNUstep Base Library is a powerful fast library of general-purpose,
non-graphical Objective C classes, inspired by the superb OpenStep API but
implementing Apple and GNU additions to the API as well. It includes for
example classes for unicode strings, arrays, dictionaries, sets, byte
streams, typed coders, invocations, notifications, notification dispatchers,
scanners, tasks, files, networking, threading, remote object messaging
support (distributed objects), event loops, loadable bundles, attributed
unicode strings, xml, mime, user defaults. This package includes development
headers too.