Windows 7 UNIX Free Resources Available for Download.
Just as it was the case with its predecessors, select editions of Windows 7 include by default a multi-user UNIX environment, designed to offer functionality specific to the open source operating system, on top of the Windows platform. In addition to the Subsystem for UNIX-based Applications (SUA), Microsoft is also offering Windows 7 users additional resources as a standalone download. Utilities and a software development kit (SDK) for Subsystem for UNIX-based Applications in Microsoft Windows 7 and Windows Server 2008 R2 are currently up for grabs via the Microsoft Download Center.
Source - Windows 7 UNIX Free Resources Available for Download - From Microsoft - Softpedia