Microsoft's Windows Subsystem for Linux [wikipedia.org] is coming to all Windows 10 users [engadget.com]:
You won't have to be a tester to try Windows 10's new, built-in Linux kernel [engadget.com] in the near future. Microsoft has confirmed [microsoft.com] that Windows Subsystem for Linux 2 will be widely available when Windows 10 version 2004 arrives. You'll have to install it manually for a "few months" until an update adds automatic installs and updates, but that's a small price to pay if you want Linux and Windows to coexist in peace and harmony. It'll be easier to set up, at least -- the kernel will now be delivered through Windows Update instead of forcing you to install an entire Windows image.
Embrace, Extend... Excite!