Object-Oriented Programming and the Objective-C Language -  .

Categorically Speaking - - Article from Stepwise on the merits of Objective-C categories, with examples.

Cetus Links - Objective-C - - Links on Objects, Components and Objective-C. Provides links on tutorial, newsletter, books, software and libraries.

Cocoa: The Objective-C Programming Language - - A detailed introduction to object-oriented programming in the context of the Objective-C programming language.

comp.lang.objective-c FAQ - - Frequently asked questions about Objective-C.

Objective-C - - At the Portland Pattern Repository Wiki.

Objective-C Beginner's Guide - - Tutorial in text and code samples. English, Chinese.

Objective-C is Fun - - A simple introduction to Objective-C, from the GNUstep project. By Adam Fedor.

Objective-C Resources - - Directory Objective-C resources.

Optimizing Objective-C Code - - Articles and samples to help you get maximum performance from your Objective-C code.

Programming in Objective-C - - Some introductory notes and examples of Objective-C.

Programming: Objective-C - - Includes tutorials, reference material and downloads.

Steve Dekorte's Objective-C page - - Overview, language comparisons, history, compilers (platform chart and feature chart), project links.

A First Look at Objective-C - - Article by Noah Roberts. (July 9, 2001)