A family of emulators from Apple for its latest Mac hardware. Named after the Rosetta Stone, which inscribed a decree in 196 BC of the Egyptian King Ptolemy V in three languages, Rosetta 1 (originally just Rosetta) ran PowerPC applications on Intel-based Macs when Apple transitioned from PowerPC to Intel x86 CPUs (see Intel Mac
). Supported on OS X versions 10.4 through 10.6, Rosetta ran all PowerPC apps except where specific G5 processor instructions were used (see G5
Rosetta 2 for ARM-Based Macs
In late 2020, Apple began switching hardware platforms once again and provided Rosetta 2 to enable Intel x86 applications to run on the latest ARM-based Macs (see Apple M series
Apple Switched Hardware Three Times
Whereas Windows PCs have run on Intel CPUs since the 1980s, Mac computers started out using Motorola CPUs but switched to PowerPC and then Intel and finally their own ARM processor. Apple did provide an emulator from Motorola to PowerPC, and parts of the PowerPC OS were actually emulated Motorola code.
Rosetta Keeps Things Going
Without Rosetta emulation, Apple would have made switching hardware very difficult for users. Rosetta gives people a few years to update their apps to the new platform.