Apple Developer Connection: Mac OS X - Apple's developer resource for Mac OS X. Contains guidelines, tutorials and API information for new OS X developers. Most documentation is available in HTML or PDF format. Cocoa Dev Central - Tips, tricks, and tutorials for the novice Cocoa developer. O'Reilly MacDevCenter - Many articles and books on a broad range of Mac OS X developer topics. AltiVec Programming - Apple's main AltiVec/Velocity Engine site including an overview, sample code and various software libraries optimized for the G4. Big Nerd Ranch - Big Nerd Ranch offers intensive, head-down Cocoa programming courses taught by experts in a retreat-style environment. Also contains information on Aaron Hillegass' book "Cocoa Programming for Mac OS X". OmniGroup Source Code and Frameworks - Open Source frameworks and source code from OmniGroup that extend and enhance Apple's Cocoa APIs, simplifying the addition of common features such as find and replace and preference management. OmniGroup also provides advanced networking and HTML parsing frameworks.