There's a new Windows 10 build available for those in the Windows Insider Program



From Windows Central:

Here's what is new in today's Windows 10 build:

Ability to hide or show Task View button
Ability to hide or show Search button
New minimize and restore animations
Three dots in Windows chrome replaced by 'hamburger-style' icon
New Trackpad gestures: 3 finger up -> Task View, 3 finger down -> show Desktop, 3 finger flick to left or right -> switches to previous app, 3 finger move left or right -> Alt-Tab appears, 3 finger tap -> Search
Selective sync available in OneDrive, you pick what you want synced to your PC now
Interoperability focused Edge rendering engine in Internet Explorer available to 10% of Insiders
Native MKV support, including thumbnail and metadata support in File Explorer
Continued UI refinements, including some new icons
New Insider Hub app for those in the Windows Insider Program

  New Windows 10 Build 9879 improves OneDrive, adds native MKV support and more