Look what the cat dragged in (with the new MSDN shipment):
Microsoft Interix gives you all the features of a traditional UNIX operating system, including pipes, hard file links, UNIX networking, and UNIX graphical support through the X Window System. It also provides UNIX and POSIX.2 utilities such as KornShell, awk, and vi. The Microsoft Interix environment is not an emulation; it is a native environment subsystem that integrates with the Windows NT kernel, just as the Win32 subsystem does. Shell scripts and other scripted applications that use UNIX and POSIX.2 utilities will run under Microsoft Interix. To port C source code from a UNIX system to Microsoft Interix, you will need the Microsoft Interix Software Development Kit.
Microsoft Interix Release 2.2 functionality includes gcc and g++, new libraries and utilities, syslogd and utmpx functions, performance improvements, and improved interoperability with other filesystems such as NFS and Samba.
Earlier releases of Microsoft Interix before release 2.2 went under the name OpenNT