Microsoft’s next major Windows 10 update, codenamed “Redstone 5,” has been in testing for a few weeks now, and the company is now ready to unveil some new features that it's experimenting with. Alongside the new Sets feature for all Windows 10 apps, Microsoft is also changing the way the Alt-Tab feature works. Instead of tabbing between apps, Microsoft is experimenting with allowing Windows 10 users to also switch between the tabs within the Sets feature inside the Alt-Tab interface.

Microsoft hasn’t overhauled its Alt-Tab task switcher for years, and this feels like a major addition. Essentially, it means Alt-Tab will now work for apps and browser tabs or app tabs. Microsoft is also working on bringing groups of tabbed apps to Timeline, its new Windows 10 feature that keeps a history of activities and webpages.

Microsoft appears to be betting on Timeline for productivity on Windows and across devices, and the company will extend this feature to both iOS and Android. Microsoft’s Android Launcher will include Timeline so you can quickly pick up webpages on the go, and the Microsoft Edge browser on iOS will include access to Timeline.

Microsoft will start testing these changes shortly with Windows Insiders, but there’s no guarantee they will all ship with the next major Windows 10 update. Microsoft’s Joe Belfiore made it clear at Build today that the company will only ship its Sets feature once it’s ready, and that same approach applies to other Windows 10 features like “Your Phone.”