According to the Wall Street Journal (subscription required), in addition to the release of the iOS 10 public beta, Apple released the public beta of macOS Sierra today. As with the iOS 10 beta, it is not advisable to install the Sierra beta on your primary Mac’s drive. Of course, if you decide to download Sierra beta anyway, be sure to back up your data. You can sign up to get access to the Sierra beta at beta.apple.com.

Among other things, Sierra adds Siri to the Mac, Apple Pay on certain websites accessed with Safari, enhancements to Photos, a Universal Clipboard that works between iOS devices and Macs, and Auto Unlock of your Mac with your Apple Watch instead of a password, which requires you also run the iOS 10 and watchOS 3 betas. For more coverage of what’s new in macOS Sierra check out our WWDC coverage.