iDevGames
Macintosh game development website featuring news, tutorials, game assets, forums and articles.

MacHack
"The Annual Conference for Leading Edge Developers"; a multi-day round-the-clock ritual involving gallons of soda, heinous hacks, and lots of camaraderie. Not to be missed!

Macdev at MIT
Various resources for Macintosh development from the folks over at MIT.

Sound & Vision, Inc.
Develop software for Macintosh platform. On this site users can find information about FineReader 5 Pro, development and layout software.

GNUstep Project
A project devoted to providing an object oriented application framework to developers.

MacOS Web Directory
A directory of Mac programming related sites, including development kits, format specs, toolkits, open source, tutorials, and webzines.

Dr. Dobb's - The Fifth Column
Good general resource including Michael Swaine's subversive perspective on the world of Macintosh development updated each month. Offers source code, online search, and book reviews.

Apple Developer Connection
Provides news and technical information for Apple Developers.

Mac OS 8 and 9 Developer Documentation
Gateway to Apple's documentation for programming Mac OS 8 and 9, including Carbon development.