LAN Manager

LAN Manager is a discontinued network operating system (NOS) available from multiple vendors and developed by Microsoft in cooperation with 3Com Corporation. It was designed to succeed 3Com's 3+Share network server software which ran atop a heavily modified version of MS-DOS. The LAN Manager OS/2 operating system was co-developed by IBM and Microsoft, using the Server Message Block (SMB) protocol. It originally used SMB atop either the NetBIOS Frames (NBF) protocol or a specialized version of the Xerox Network Systems (XNS) protocol. These legacy protocols had been inherited from previous products such as MS-Net for MS-DOS, Xenix-NET for MS-Xenix, and the afore-mentioned 3+Share. A version of LAN Manager for Unix-based systems called LAN Manager/X was also available. LAN Manager/X was the basis for Digital Equipment Corporation's Pathworks product for OpenVMS, Ultrix and Tru64. Despite support from 3Com, IBM, Digital, and Digital Communications Associates, PC wrote in 1989, LAN Manager "has made a very small impression on the market and continues to receive the cold shoulder from buyers" compared to Novell NetWare. The combined companies "pose a strong potential threat", however, the magazine added. In 1990, Microsoft announced LAN Manager 2.0 with a host of improvements, including support for TCP/IP as a transport protocol for SMB, using NetBIOS over TCP/IP (NBT).