MacOS 12.0

macOS 12.0 (build 21A344) is the first public release of macOS 12 (Monterey) in October 2021 by Apple Inc. Though it came pre-installed on early shipments of Apple M1 Pro and M1 Max-based MacBook Pros, security updates necessitated macOS 12.0.1 becoming the first standalone release of Monterey to the general public on October 25, 2021, in a similar situation as macOS 11.0 to 11.0.1 for the first M1-based Macs during the previous year.

Development history
The first developer beta (build 21A5248p) of macOS 12.0 was seeded on June 7 during the 2021 Worldwide Developers Conference. The second developer beta (build 21A5268h) was released on June 28, and again on July 1st as the first public beta.