Third party

Third party refers to products from a hardware or software developer and/or publisher that is not directly associated with the creator or developer of the platform itself.

First party
Apple's own iTunes software, or FileMaker from its Claris subsidiary, can be considered first-party software as both the software and the developer are owned by the creator of the platform.

Second party
Switcher was created by Andy Hertzfeld when he was an independent contractor for Apple Computer. It was acquired by Apple and could be considered second-party at the time as the software, but not the developer, is owned by the creator of the platform. These circumstances have become non-existent as Apple now tends to buy out development and technology outright. If the software and development team are both acquired, as in the case of Final Cut Pro, then it would become a first-party product.

Third party
Software from another developer that is bundled or promoted by Apple, such as Nanosaur or YouTube, or produced by a direct competitor, such as Microsoft Office for Mac, are considered third-party software as neither the software nor the developer are owned by the creator of the platforms (macOS and iOS). Apple now generally only bundles software that had been developed internally.

History at Apple
One of Apple's early third-party licenses was for distribution of Applesoft BASIC, which was developed from Microsoft's source code to bring support to the Apple II in 1978. However, this arrangement later led Microsoft to pressure then-Apple CEO John Sculley into selling them a perpetual license to the Macintosh user interface and MacBASIC (which Microsoft scuttled) for $1 in exchange for an extension of the Applesoft license in November 1985. After co-founder Steve Jobs returned to Apple, the company bundled games to promote the graphics capabilities of its iMac G3 line. Apple now avoids including third party software with its hardware products. Even free apps for Netflix and YouTube must be downloaded to current Apple TV models from the App Store.

Security
For mobile devices running iOS and its derivatives such as iPadOS, Apple limits installation of third-party software to what is available for download through its App Store. Apple insists that this is for security of the platform from malware. Critics have compared this closed arrangement to a "". Installation outside of the App Store would require jailbreaking the device, which would void its warranty. Apple has been gradually applying similar restrictions to macOS through Gatekeeper and Secure Enclave. To allow software to be installed from outside the Mac App Store, a user with administrator permissions can access the feature through the Security & Privacy pane of System Preferences.