Windows 10 build 17057 is now going through internal testing. The new Redstone 4 Update build 17057 (10.0.17057.1000 rs_prerelease.171206-1516) was compiled on Dec 06, 2017. Windows 10 Mobile build 15254.17 was compiled on the same day.
In coming weeks, Insider team will release two major Windows 10 features – Sets and Timeline. The new Windows 10 Sets features will allow users to group apps into various tabs, similar to tabs in a web browser.
Whereas with the Timeline feature, you will able to “jump back in time”, so you can find files, apps, and websites that you were working on previously.
Previously, Windows 10 Redstone 4 update build 17046 released with fixes and improvements.