Xsun is an X Window System

X Window System

The X window system is a computer software system and network protocol that provides a basis for graphical user interfaces and rich input device capability for networked computers...

 (X11) server implementation included with the Solaris operating system

Solaris Operating System

Solaris is a Unix operating system originally developed by Sun Microsystems. It superseded their earlier SunOS in 1993. Oracle Solaris, as it is now known, has been owned by Oracle Corporation since Oracle's acquisition of Sun in January 2010....

, developed by Sun Microsystems

Sun Microsystems

Sun Microsystems, Inc. was a company that sold :computers, computer components, :computer software, and :information technology services. Sun was founded on February 24, 1982...

. It replaced the older "Xnews" server, which supported the display of not only X11 applications, but also NeWS

NeWS

NeWS was a windowing system developed by Sun Microsystems in the mid 1980s. Originally known as "SunDew", its primary authors were James Gosling and David S. H. Rosenthal...

 and SunView

SunView

SunView was a windowing system from Sun Microsystems developed in the early 1980s. It was included as part of SunOS, Sun's UNIX implementation; unlike later UNIX windowing systems, much of it was implemented in the system kernel...

 programs. Xsun removed support for these legacy environments, and added support for Display PostScript

Display PostScript

Display PostScript is an on-screen display system. As the name implies, DPS uses the PostScript imaging model and language to generate on-screen graphics...

.

Xsun was first released as part of Solaris 2.3 in November 1993. It was originally based on X11 Release 5; the version included with Solaris 10 is based on X11R6.6.

Solaris 10 includes both Xsun and the X.Org Server

X.Org Server

X.Org Server refers to the X server release packages stewarded by the X.Org Foundation,which is hosted by freedesktop.org, and grants...

, the open-source software

Open-source software

Open-source software is computer software that is available in source code form: the source code and certain other rights normally reserved for copyright holders are provided under a software license that permits users to study, change, improve and at times also to distribute the software.Open...

 reference implementation

Reference implementation

In the software development process, a reference implementation is the standard from which all other implementations, with their attendant customizations, are measured, and to which all improvements are added...

 of X, based on X11R7. The "Xorg" server is the most commonly used server for x86 systems, and the Xsun server remains the most commonly used for SPARC

SPARC

SPARC is a RISC instruction set architecture developed by Sun Microsystems and introduced in mid-1987....

 systems; Xorg support for SPARC was only added in Solaris 10 8/07, and has very limited driver support. The OpenSolaris

OpenSolaris

OpenSolaris was an open source computer operating system based on Solaris created by Sun Microsystems. It was also the name of the project initiated by Sun to build a developer and user community around the software...

project has stated that the future direction for X support is via the Xorg implementation.