Windows Services for UNIX

Windows Services for UNIX (SFU) is a discontinued software package produced by Microsoft which provided a Unix environment on Windows NT and some of its immediate successor operating systems. SFU 1.0 and 2.0 used the MKS Toolkit; starting with SFU 3.0, SFU included the Interix subsystem, which was acquired by Microsoft in 1999 from US-based Softway Systems as part of an asset acquisition.