SunOS 2.0

Sun UNIX 4.2 Release 2.0 (aka SunOS 2.0) is a version of SunOS. Based on 4.2BSD, just like previous releases. SunOS 2.0 introduced the NFS protocol, a distributed file system protocol which is still being used to this day, Yellow Pages (yp, now known as NIS), RPC (Remote Procedure Call), XDR, and the virtual file system. Coincided with the launch of Sun's Sun-3 hardware.