Larger developers like Microsoft and Adobe balked outright, and refused to consider porting to Open Step, which was so different from the existing Mac OS that there was little or no compatibility. When Steve Jobs announced this change in direction at the 1998 WWDC, he stated that "what developers really wanted was a modern version of the Mac OS, and Apple [was] going to deliver it". The original Rhapsody concept was eventually released in 1999 as Mac OS X Server 1.0, the only release of its type.
Developers could use the Carbon APIs to port their "classic" Mac software to the Mac OS X platform with far less effort than a port to the entirely different Cocoa system, which originated in OPENSTEP.
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.
One of the biggest changes that you should be aware of with i OS 11 is the deprecation of 32-bit support for apps, as detailed in Apple's press release.
This guide guides you through updating your app for 64-bit.
These promotions include updates to in-app purchases and updates to the product page.