Well, you are surprised to see the title. Are n't you? You might be thinking what does that even mean. In microsoft build developer's conference, it was revealed that microsoft is planning to create a ubuntu user space in Windows, which will help you to run Ubuntu applications in natively in Windows.
|source : http://blog.dustinkirkland.com|
Is it a virtual machine running on windows? No. It is not a virtual machine. There is no Linux Kernel at all. It is just user space where you can access and use Ubuntu programs.Read complete article written by Dustin Kirkland, a team member of Canonical attending microsoft build developer conference, to know more details.
Cygwin is already running a lot of Linux commands. Then What? Cygwin is actually using tools which are specifically compiled to run on windows platform. Newly developing user space will be running ubuntu applications without any rebuild.
Then what the *** is that? Are you familiar with WINE? A windows binary running platform for linux distributions? Yes. What does it do? It will map all windows system calls to linux system calls on real time. Ubuntu user space for windows is something similar to that. Microsoft calls it as Windows Subsystem for Linux.