Microsoft is testing a new build of Windows 10 today (17666) that includes some new features that will be available later this year. The biggest addition is a new cloud-powered clipboard that will let Windows 10 users roam their clipboard contents across devices, and presumably eventually to Android and iOS devices. The cloud clipboard includes a history of what has been copied, and it will sync in the same way Sets and Timeline do, so you can copy from one PC and paste on another.

Alongside the cloud clipboard, Microsoft is also bringing a dark theme to File Explorer to match the rest of the Windows 10 dark user interface. The new build doesn’t have a full version of the dark theme just yet, but Microsoft is previewing how it will eventually look in Windows 10. Microsoft is even making some minor changes to Notepad, allowing developers to use Unix / Linux line endings (LF) and Macintosh line endings (CR) in the app. You can also highlight words in Notepad and use a keyboard shortcut or context menu item to search Bing for the word.

Microsoft is also making some subtle changes to Fluent Design in this latest test version of Windows 10. Sets now have an acrylic title bar, and the Alt-Tab experience now includes recent Microsoft Edge tabs to switch between. You can disable this new Alt-Tab change in multitasking settings, and this subtle improvement joins the new screenshot tool for Windows 10. The new Windows 10 build 17666 is available to Fast Insiders immediately, and the features should be available to Windows 10 users later this year.