As has become tradition at WWDC, Apple has announced the next version of its Mac operating system: Sierra. Of course, the real change is that, after fifteen years, Apple has finally ditched the "OS X" moniker. All things old are new again, and the new operating system will simply be called "macOS." We don't yet know if Sierra carries a "10.12" version number, but with developers getting their hands on the OS later today, we should soon have that question answered.

Apple's Craig Federighi ran through a whole bunch of new features to be included in the revised operating system. He started by mentioning Continuity and Auto-Unlock, which now combine to let you seamlessly unlock a desktop or laptop Mac merely by bringing your Apple Watch close, using what Federighi described as "time-of-flight networking" to detect the watch's proximity. It was unclear from the presentation whether or not this feature is an Apple Watch exclusive; Federighi did not explicitly say that Auto-Unlock would work with iOS devices.

Another Continuity-based feature showing up in Sierra is Universal Clipboard, which answers a longstanding complaint of Mac and iOS users. Copying and pasting now works automatically between an iOS device and a desktop Mac device. This appears to be a bidirectional service; you can copy an item to your iOS clipboard and see it on the desktop, and vice versa.

iCloud now plays an expanded sync role, too, letting you move files and folders from Mac to Mac or from Mac to iOS. Another new feature called Optimized Storage can sweep through old files and push them to iCloud, clearing up local disk space for other uses. It also can automatically dump your trash, clear your Web history, and do other behind-the-scenes sweeps. Federighi noted that in one test situation, Apple used Optimized Storage to free up 130GB of local storage.

After making their appearance in the Finder with the last big OS X (ahem, macOS) revision, tabs are now coming to more applications. Federighi said that Apple wants tabs on all multi-window applications, and he added that getting them there can be done without developer modification. We're not sure exactly how this works, but we're eager to see it demonstrated.



Apple Pay will also come to the Mac, after some delay. The above picture was flashed up on the screen as a joke before Federighi explained that Apple Pay will be usable from desktop browsers, using TouchID or an Apple Watch to authenticate via Continuity.

Siri, of course

In probably the worst-kept secret of the show, Apple formally announced that Siri is coming to the desktop. After allowing Siri to introduce herself—shades of the original 1984 Mac demo!—Federighi showed off several Siri desktop features that should look familiar to iOS users. In addition to doing context-sensitive searches, calling up playlists, and creating tasks, Federighi used Siri to kick off Web searches and then used the Siri search results to complete a Keynote presentation.

As anticipated, the feature looks and acts a lot like Cortana on Windows 10.

When?

Sierra will be available to developers today and will have a public beta in July. The operating system is set for a fall 2016 general release.

This story is developing; details will be added as the event continues.