Solaris

Solaris is a Unix operating system originally developed by Sun Microsystems. It superseded their earlier SunOS in 1993. In 2010, after the Sun acquisition by Oracle, it was renamed Oracle Solaris.

Solaris is known for its scalability, especially on SPARC systems, and for originating many innovative features such as DTrace, ZFS and Time Slider. Solaris supports SPARC and x86-64 workstations and servers from Oracle and other vendors. Solaris is registered as compliant with the Single UNIX Specification.

Historically, Solaris was developed as proprietary software. In June 2005, Sun Microsystems released most of the codebase under the CDDL license, and founded the OpenSolaris open-source project. With OpenSolaris, Sun wanted to build a developer and user community around the software. After the acquisition of Sun Microsystems in January 2010, Oracle decided to discontinue the OpenSolaris distribution and the development model.[8][9] In August 2010, Oracle discontinued providing public updates to the source code of the Solaris kernel, effectively turning Solaris 11 back into a closed source proprietary operating system. Following that, OpenSolaris was forked as Illumos and is alive through several Illumos distributions.

In 1987, AT&T Corporation and Sun announced that they were collaborating on a project to merge the most popular Unix variants on the market at that time: Berkeley Software Distribution, UNIX System V, and Xenix. This became Unix System V Release 4 (SVR4).

On September 4, 1991, Sun announced that it would replace its existing BSD-derived Unix, SunOS 4, with one based on SVR4. This was identified internally as SunOS 5, but a new marketing name was introduced at the same time: Solaris 2], The justification for this new overbrand was that it encompassed not only SunOS, but also the OpenWindows graphical user interface and Open Network Computing (ONC) functionality.

Although SunOS 4.1.x micro releases were retroactively named Solaris 1 by Sun, the Solaris name is used almost exclusively to refer only to the releases based on SVR4-derived SunOS 5.0 and later.

For releases based on SunOS 5, the SunOS minor version is included in the Solaris release number. For example, Solaris 2.4 incorporates SunOS 5.4. After Solaris 2.6, the 2. was dropped from the release name, so Solaris 7 incorporates SunOS 5.7, and the latest release SunOS 5.11 forms the core of Solaris 11.4.

Although SunSoft stated in its initial Solaris 2 press release their intent to eventually support both SPARC and x86 systems, the first two Solaris 2 releases, 2.0 and 2.1, were SPARC-only. An x86 version of Solaris 2.1 was released in June 1993, about 6 months after the SPARC version, as a desktop and uniprocessor workgroup server operating system. It included the Wabi emulator to support Windows applications. At the time, Sun also offered the Interactive Unix system that it had acquired from Interactive Systems Corporation. In 1994, Sun released Solaris 2.4, supporting both SPARC and x86 systems from a unified source code base.

On September 2, 2017, Simon Phipps, a former Sun Microsystems employee not hired by Oracle in the acquisition, reported on Twitter that Oracle had laid off the Solaris core development staff, which many interpreted as sign that Oracle no longer intended to support future development of the platform.[19] While Oracle did have a large layoff of Solaris development engineering staff, development continues today of which Solaris 11.4 was released in 2018.