Cocoa is Apple Inc.’s native object-oriented application programming environment for the Mac OS X operating system. It is one of five major APIs available for Mac OS X; the others are Carbon, Toolbox (for the obsolete Classic environment), POSIX (for the BSD environment), and Java.
Cocoa applications are typically developed using the development tools provided by Apple, specifically Xcode (formerly Project Builder) and Interface Builder, using the Objective-C language. However, the Cocoa programming environment can be accessed using other tools, such as Python, Perl and Ruby, with the aid of bridging mechanisms such as PyObjC, CamelBones and RubyCocoa, respectively. It is also possible to write Objective-C Cocoa programs in a simple text editor and build it manually with GCC or GNUstep’s makefile scripts.
Scott Stevenson has posted the video for the Introduction to Cocoa talk at CocoaHeads. Do note that both videos are pretty big and therefore, you might want to consider downloading it via BitTorrent.
