List of Apple codenames

The list of Apple codenames covers the codenames given to products by Apple Inc. during development. The codenames are often used internally only, normally to maintain the secrecy of the project. Occasionally a codename may become the released product's name. Most of Apple's codenames from the 1980s and 1990s are provided by the book "Apple Confidential 2.0".
Apple-designed processors.
Apple-designed A series processors' internal codenames are named after wind and weather patterns.
Software.
AirPods Firmware.
For use with AirPods
audioOS.
For use with HomePod
Classic Mac OS.
The classic Mac OS is often cited as having multiple codenames. The codename convention for Mac OS 8 and 9 mostly follow musical terminology.
iOS.
The codename convention for iOS are ski resorts.
Mac OS X/OS X/macOS.
The internal codenames of Mac OS X 10.0 through 10.2 are big cats.
In Mac OS X 10.2, the internal codename "Jaguar" was used as a public name, and, for subsequent Mac OS X releases and for OS X 10.9, big cat names were used as public names and wine names were used as internal codenames.
For OS X releases beginning with 10.10, and for macOS releases, landmarks in California were used as public names.
For OS X releases beginning with 10.11, and for macOS releases, varieties of apples were used as internal code names.