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 It superseded their earlier SunOS in 1993.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.

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-based and x86-based workstations and servers from Sun and other vendors, with efforts underway to port to additional platforms. Solaris is registered as compliant with the Single Unix Specification.

Solaris was historically developed as proprietary software, then 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. Just ten days before the internal Oracle memo announcing this decision to employees was "leaked", Garrett D'Amore had announced[8] the illumos project, creating a fork of the Solaris kernel and launching what has since become a thriving alternative to Oracle Solaris.

In August 2010, Oracle discontinued providing public updates to the source code of the Solaris Kernel, effectively turning Solaris 11 into a closed source proprietary operating system. However, through the Oracle Technology Network (OTN), industry partners can still gain access to the in-development Solaris source code. Source code for the open source components of Solaris 11 is available for download from Oracle.

Supported Architectures

Solaris uses a common code base for the platforms it supports: SPARC and i86pc (which includes both x86 and x86-64).

Solaris has a reputation for being well-suited to symmetric multiprocessing, supporting a large number of CPUs. It has historically been tightly integrated with Sun's SPARC hardware (including support for 64-bit SPARC applications since Solaris 7), with which it is marketed as a combined package. This has often led to more reliable systems, but at a cost premium over commodity PC hardware. However, it has also supported x86 systems since Solaris 2.1 and it includes support for 64-bit x86 applications since Solaris 10, allowing Sun to capitalize on the availability of commodity 64-bit CPUs based on the x86-64 architecture. Sun has heavily marketed Solaris for use with both its own "x64" workstations and servers based on AMD Opteron and Intel Xeon processors, as well as x86 systems manufactured by companies such as Dell, Hewlett-Packard, and IBM. As of 2009, the following vendors support Solaris for their x86 server systems:

• Dell - will "test, certify, and optimize Solaris and OpenSolaris on its rack and blade servers and offer them as one of several choices in the overall Dell software menu"
• IBM - also distributes Solaris and Solaris Subscriptions for select x86-based IBM System x servers and BladeCenter servers
• Intel
• Hewlett-Packard - distributes and provides software technical support for Solaris on ProLiant server and blade systems
• Fujitsu Siemens

Installation and usage options

Solaris can be installed from various pre-packaged software groups, ranging from a minimalistic "Reduced Network Support" to a complete "Entire Plus OEM". Installation of Solaris is not necessary for an individual to use the system. Additional software, like Apache, MySQL, etc. can be installed as well in a packaged form from sunfreeware, OpenCSW and Blastwave.

Usage with installation
Solaris can be installed from physical media or a network for use on a desktop or server.

Solaris can be interactively installed from a text console on platforms without a video display and mouse. This may be selected for servers, in a rack, in a remote data center, from a terminal server or even dial up modem.

Solaris can be interactively installed from a graphical console. This may be selected for personal workstations or laptops, in a local area, where a console may normally be used.

Solaris can be automatically installed over a network. System administrators can customize installations with scripts and configuration files, including configuration and automatic installation of third-party software, without purchasing additional software management utilities.

When Solaris is installed, the operating system will reside on the same system where the installation occurred. Applications may be individually installed on the local system, or can be mounted via the network from a remote system.

Usage without installation
Solaris can be used without separately installing the operating system on a desktop or server.

Solaris can be booted from a remote server providing an OS image in a diskless environment, or in an environment where an internal disk is only used for swap space. In this configuration, the operating system still runs locally on the system. Applications may or may not reside locally when they are running. This may be selected for businesses or educational institutions where rapid setup is required (workstations can be "rolled off" of a loading dock, the MAC address registered into a central server, plugged in, and be immediately usable) or rapid replacement is required (if a desktop hardware failure occurs, a new workstation is pulled from a closet, plugged in, and a user can resume their work from their last saved point.)

Solaris can also be used from a thin client. Applications, operating system, window manager, and graphical rendering runs on one or more remote servers. Administrators can add a user account to a central Solaris system and a thin client can be rolled from a closet, placed on a desktop, and a user can start work immediately. If there is a hardware failure, the thin client can be swapped and the user can resume their work from the exact point of failure, whether or not the work was saved.