Carbon (API)

Carbon was one of two primary C-based application programming interfaces (APIs) developed by Apple for the macOS (formerly Mac OS X and OS X) operating system. Carbon provided a good degree of backward compatibility for programs that ran on Mac OS 8 and 9. Developers could use the Carbon APIs to port (“carbonize”) their “classic” Mac applications and software to the Mac OS X platform with little effort, compared to porting the app to the entirely different Cocoa system, which originated in OPENSTEP. With the release of macOS 10.15 Catalina, the Carbon API was officially discontinued and removed, leaving Cocoa as the sole primary API for developing macOS applications.

Carbon was an important part of Apple's strategy for bringing Mac OS X to market, offering a path for quick porting of existing software applications, as well as a means of shipping applications that would run on either Mac OS X or the classic Mac OS. As the market has increasingly moved to the Cocoa-based frameworks, especially after the release of iOS, the need for a porting library was reduced. Apple did not create a 64-bit version of Carbon while updating their other frameworks in the 2007 time-frame, and eventually deprecated the entire API in OS X 10.8 Mountain Lion, which was released on July 24, 2012.