Aside from releasing iOS 11 public beta 2, Apple this morning posted a second public beta for macOS High Sierra. It has the same features (and bugs) like developer-only beta 3 seeded to registered developers and members of the paid Apple Developer Program two days ago.
To install the public beta of High Sierra on your computer, sign up for Apple’s Beta Software Program by signing in with your Apple ID in Safari on your Mac at beta.apple.com
Next, click the “Enroll Your Devices” link on the webpage to download the macOS Public Beta Access Utility, which will enable your computer to receive public beta software through the Software Update mechanism via the Mac App Store’s Updates tab.
To check if your computer is enrolled in the beta program, open System Preferences and click the App Store icon. A message will appear saying “your computer is set to receive beta software update” if your Mac is enrolled in the program.
macOS High Sierra includes new features like the Apple File System, support for the new High Efficiency Video Codec (HEVC), also known as H.265, an updated version of Metal with support for VR applications and external GPU enclosures, Safari 11 with new anti-tracking features, support for flight status information in Spotlight, more natural voices for Siri and more.
FaceTime, Messages, Notes and other stock apps have been updated with various enhancements, including the Photos app which now has a new sidebar, curve-based editing and support for editing in third-party apps like Pixelmator and Photoshop.
High Sierra will release for public consumption this fall for supported Mac models.