(1) An earlier network operating system from IBM that ran as a server application under OS/2 and supported DOS, Windows and OS/2 clients. Originally based on LAN Manager when OS/2 was jointly developed by IBM and Microsoft, starting with LAN Server 3.0, it ran only under IBM's version of OS/2. LAN Server provided disk mirroring, CID capability and Network Transport Services/2 (NTS/2) for concurrent access to NetWare servers. Options were LAN Server for the Macintosh for Mac client access and System Performance/2 (SP/2), a series of network management utilities. See CID.
(2) (LAN server) A file server in a local area network (LAN). See file server.