i know c and I want to develop applications with GUI for Mac OS. Where do I start?
Learn Objective-C.
Then pick up Cocoa (and all of the Frameworks that go with it)
Downloading xcode would be your first step. It's the main development environment for mac development and it's free. Then you'd want to get a book on Cocoa w/ Objective-C or Carbon w/ C. Apple is pushing Cocoa more.
I believe all Macs nowadays come with a complete set of development tools. They're not pre-loaded on the Mac, but are in the CD-ROM or DVD-ROM package. Alternately, you can go to Apple's site and poke around until you find the development section, and download Xcode. (It'll be the same thing, but possibly a newer version.)
Mac OSX uses a language called Objective-C, which is C extended with OO abilities that are more like Smalltalk than the more usual Simula type (in C++, say). While you don't actually have to use it much, it is how you'll be writing interface code.
Further, it uses the Cocoa framework. There was a framework called Carbon, which was a cleanup and redesign of the pre-Mac OSX Macintosh system facilities, but it's being left behind.
You can find free information on either if you look, or you can buy books on them. Books are probably a better resource to learn from.
- Buy Apple computer
- Install XCode from supplied DVD
- Run Software Update from system menu
- Run XCode
- Select Help menu, select "Developer Documentation"
- Click on any of the many things that say things like "Quick Start" or "Getting Started with XCode".
- Read
- Program
- GoTo 7.