Apple's first public beta of macOS Sierra is available today via the Mac App Store.
Developers have had their hands on macOS Sierra since it was unveiled at WWDC, but now anyone who signs up for Apple's beta program can try it out, too.
Ahead of today's launch, Apple added stability updates, a new Siri keyboard shortcut (command-space hold), and Auto Unlock to Sierra. The latter, which lets Apple Watch wearers open a Sierra-run Mac, is currently available only to registered developers using the beta version of watchOS 3.
The next-gen OS, which arrives for everyone in the fall, is now open to anyone adventurous enough to test it out. Just remember: The software is still in development, and some applications or services may not work as expected. Cupertino also encourages early-bird users to make a backup of their computers. If possible, install macOS Sierra beta on a secondary Mac—one that you're not super attached to, should anything go wrong.
Keep an eye out for periodic updates rolling out over the coming months, and report any issues directly to Apple via the built-in Feedback Assistant app.
Among the features in Sierra are a new storage optimizer that deletes Web caches and other unused files, freeing up gigabytes of space. Apple also teased "tabs everywhere" in Safari, as well as Picture-in-Picture for multitasking. Apple Pay is also coming to the browser and more countries; it landed in Switzerland today.
For more, check out What MacOS Sierra's New APFS File System Means to You.