Universal binary

With the release of Mac OS X Snow Leopard, and before that, since the move to 64-bit architectures in general, some software publishers such as Mozilla[1] have used the term "universal" to refer to a fat binary that includes builds for both i386 (32-bit Intel) and x86_64 systems.

Universal binaries were introduced into Mac OS at the 2005 Apple Worldwide Developers Conference as a means to ease the transition from the existing PowerPC architecture to systems based on Intel processors, which began shipping in 2006.

This allows the application to run natively on any supported architecture, with no negative performance impact beyond an increase in the storage space taken up by the larger binary.

[5] Universal 2 allows applications to run on both Intel x86-64-based and ARM64-based Macintosh computers, to enable the transition to Apple silicon.

These reasons have been given for the delay between the introduction of Intel-based Macintosh computers and the availability of third-party applications in universal binary format.

Apple's delivery of Intel-based computers several months ahead of their previously announced schedule is another factor in this gap.

[7] From 2006 to 2010, many Mac OS X applications were ported to Universal Binary format, including QuarkXPress, Apple's own Final Cut Studio, Adobe Creative Suite, Microsoft Office 2008, and Shockwave Player with version 11 - after that time most were made Intel-only apps.

[5] The main tool for handling (creating or splitting) universal binaries is the lipo command found in Xcode.

The file command on macOS and several other Unix-like systems can identify Mach-O universal binaries and report architecture support.