In a further step in its somewhat belated move towards Unix and to open systems, Xerox Corp has released a version of its established XNS Xerox Network Services protocols for Unix System V.3. The software was developed jointly by the Xerox Systems Institute and software house Mentat Inc of Camarillo, California, and provides networking services for electronic mail, remote filing and printing, document interchange and encoding, and gateway access over a distributed networking environment. XNS protocols, which pre-dated and influenced the ISO Open Systems Interconnection seven layer reference model, specified in 1981, and Xerox says it is committed to supporting a full and robust OSI implementation compatible with the emerging standard. XNS is aimed at providing sophisticated networking for Unix users, but although Xerox claims that 700 companies have purchased the documentation needed to implement the various XNS protocols (which are in the public domain), the most immediate benefit will be access to the Xerox Network System Architecture, including Xerox workstations, networked laser printers supporting the Interpress page description language, file servers and facsimile transceivers. The system enables remote log-in from Xerox systems to Unix hosts, and file transfer between Unix and Xerox systems. The company hopes to encourage manufacturers and large system developers to produce their own XNS applications: the first two licensees are Unisys Corp and Intergraph Corp, and Xerox says that it is working with a number of other major systems and peripheral manufacturers on OEM licensing agreements for the software.