Leopard Guides: Legacy Documents

As Core Foundation and Mac OS X evolve, the APIs and technologies they encompass change to meet the needs of users and developers. As part of this evolution, less efficient features, interfaces, and programming techniques are retired or not recommended in favor of newer ones. Apple makes these changes only when deemed absolutely necessary. Apple identifies unrecommended API in header files and the ADC Reference Library. Availability macros (defined in /usr/include/AvailabilityMacros.h) further help developers find these interfaces in their source code. Comments in header files and corresponding reference documentation provide information about recommended replacements. Legacy documents help developers identify replacements and update their products to run on current Apple platforms.