Rosetta 2

Rosetta 2, part of Project Kalamata, is an initiative within Apple Inc. to facilitate the transition of the Mac product line from Intel processors to its own processors through the use of emulation.

History
Apple had previously announced that it would switch from PowerPC processors to Intel processors in 2005 when IBM's development of the PowerPC G5 could no longer keep up with its product road map. An earlier version of Rosetta was a key component of the transition by allowing PowerPC software to run in emulation on Intel processors.

In April 2008, Apple acquired P.A. Semi for $278 million to bring fabless processor design in-house to the company, and to reduce its dependence on Samsung for central processing units in its mobile products, and later Intel for its desktop products.

Development and announcement
Apple initiated Project Kalamata in 2018 and is believed to have processors based on a 5nm version of the Apple A14 ready to replace Intel as soon as 2021, starting with entry level Macs. Craig Federighi announced Rosetta 2 at 2020 Worldwide Developers Conference on June 22. It allows emulation of Intel processors on systems built around Apple processors, such as the 2020 Developer Transition Kit, which uses an Apple A12Z processor.