I have been following the buzz around the subject a bit lately, and from what I can read to most this seems to be a new feature to Windows. It is a cool feature to have in Windows, and it will be even better if it were a fully functional Linux system and not just some parts of it.
But what I have problem with is that most of the buzz is forgetting the POSIX/Unix systems that have been part of Windows since Windows NT 3.5 (yes that early). At that time, Linux was still in its infancy, so Microsoft concentrated on Unix or rather just POSIX to start with. From Windows NT 3.5 through Windows 2000 (NT 5.0) users were able to install
Microsoft POSIX subsystem. I have never used Posix subsystem, but Microsoft did implement the standard POSIX.1 (ISO/IEC 9945-1:1990) in the subsystem.
Windows XP (NT 5.1) and Windows Server 2003 (NT 5.2) had a version of Unix subsystem called
Windows Services for UNIX. From Windows Server 2003 R2 (NT 5.2) through Windows Server 2012 (NT 6.2), the subsystem was simply called
Subsystem for UNIX-based Applications. From Windows NT 5.2 kernel Unix subsystem was only available in either Server or Business/Enterprise editions of Windows.
In Windows Server 2012 R2 (NT 6.3), the Unix subsystem was almost completely removed. Only
NFS 4.1 remained from Unix subsystems in NT 6.3.
Now with the Redstone 1 update, Microsoft is going to introduce POSIX again to the Windows. In Windows 10, the subsystem is based on Ubuntu distribution of Linux. And I am looking forward to give it a spin as soon as I can install it.