Apple has released the sixth beta version of macOS Big Sur to users who are registered in the beta testing program.
Typically a developer beta version comes out first and is soon followed by a public beta release of the same build.
Separately, Apple also released iOS 14 beta 7 and iPadOS 14 beta 7 for iPhone, iPod touch, and iPad, along with new beta updates to watchOS 7 and tvOS 14.
Beta system software is less stable than final versions, but technically speaking anyone with a Big Sur compatible Mac can install the macOS Big Sur public beta right now. Due to the buggy nature of beta system software, it’s recommended to only install beta software on secondary devices that are not mission critical.