Release of SunOS 4.0 with OpenWindows

Sun Microsystems officially released SunOS 4.0, which for the first time bundled OpenWindows as its default graphical environment, featuring the X Window System and OPEN LOOK GUI.

Significance

This marked OpenWindows' debut as Sun's integrated desktop solution, offering a consistent and powerful graphical interface to its Unix workstations, setting it apart from command-line-only systems and fragmented GUI offerings.