While Microsoft is preparing the major update of Windows 10, targeting this Spring, the development team has already started working on the next feature branch Redstone 5 (RS5) and delivered the second build (17618) to insiders who opted for Skip Ahead.

The new build brings back the feature 'Sets' which allows users to group apps in a set of tabs. To know more about the features and fixes, check this post.

Microsoft started rolling out the first Redstone 5 build (Windows 10 Insiders Preview Build 17604) to the Windows Insiders, who have opted into Skip Ahead. As there's a limited space into Skip Ahead and that's already filled, no new registrations are now being accepted.

If you are a Windows Insider in the Fast Ring, you already have a fresh preview build 17101, which is already started rolling out.