IRIX
| Company type | Operating system |
|---|---|
| Industry | Computer software |
| Predecessor | GL2 (UniSoft UniPlus System V Unix-based OS) |
| Founded | 1988 |
| Founder | Silicon Graphics (SGI) |
| Defunct | 2006 (discontinued manufacturing), 2013 (end of official support) |
| Fate | Discontinued; technologies open sourced |
| Headquarters | Mountain View, California , United States |
Area served | Workstations and servers using MIPS architecture |
| Products | IRIX operating system |
| Owner | Silicon Graphics (original), later Rackable Systems, then Hewlett Packard Enterprise |
IRIX (, , a blend of IRIS and UNIX) was an operating system created by Silicon Graphics (SGI) specifically for their proprietary MIPS workstations and servers. This discontinued OS was built upon UNIX System V enhanced with BSD features, and it introduced innovations such as the XFS file system alongside the widely adopted OpenGL graphics API.
History
The name IRIX was first applied with the 1988 launch of version 3.0, designed for the SGI IRIS 4D lineup. Prior releases were labeled with "4D1-" prefixes. Before the advent of IRIX, SGI’s systems operated on GL2, an OS based on UniSoft UniPlus System V Unix, which incorporated the proprietary MEX windowing interface.
Versions in the 3.x series of IRIX merged UNIX System V Release 3 with enhancements from 4.3BSD, featuring the 4Sight window system built upon NeWS and IRIS GL. During this period, SGI replaced the standard System V filesystem with its own Extent File System (EFS).
In 1991, IRIX 4.0 transitioned from the 4Sight environment to adopting the X Window System (X11R4), utilizing the 4Dwm window manager to preserve a consistent user interface.
The 1993 release of IRIX 5.0 integrated elements from UNIX System V Release 4, including support for executables in the ELF. Subsequently, IRIX 5.3 introduced the journaling-capable XFS file system.
With IRIX 6.0 in 1994, support was added for the 64-bit MIPS R8000 processor; later updates in the 6.x series extended this to other MIPS CPUs operating in 64-bit mode. The release of IRIX 6.3 was exclusive to the SGI O2 workstation model. Enhancements in IRIX 6.4 improved scalability for multiprocessor configurations found in systems like Octane, Origin 2000, and Onyx2—the latter two versions branded as "Cellular IRIX," incorporating aspects of SGI’s distributed OS research.
The last major iteration, IRIX 6.5, debuted in May 1998 and was followed by quarterly minor revisions until 2005, plus four further updates afterward. Up through version 6.5.22, updates were categorized into maintenance ("m") and feature ("f") branches; later releases necessitated an active SGI support agreement.
A Computerworld article from 2001 characterized IRIX’s status as "critical," reflecting SGI’s strategic pivot toward Linux and Windows platforms exemplified by products like the SGI Visual Workstation. Despite this shift, client demand maintained MIPS and IRIX support until 2006. On September 6, 2006, SGI declared the discontinuation of its MIPS and IRIX lines; manufacturing ended on December 29, 2006, with official support concluding in December 2013.
Key technologies originating in IRIX—such as XFS and OpenGL—have since been open sourced by SGI and ported to Linux environments.
Following SGI’s bankruptcy filing in 2009, Rackable Systems acquired the company, which was subsequently purchased by Hewlett Packard Enterprise in 2016. After 2007, SGI hardware transitioned to IA-64 or x86-64 architectures running Linux distributions like Red Hat Enterprise Linux or SUSE Linux Enterprise Server, thereby ending compatibility with IRIX. To date, HPE has not announced any intentions to release or develop IRIX source code.
Features
IRIX version 6.5 conforms to standards including UNIX System V Release 4, UNIX 95, and POSIX, encompassing draft specifications for Access Control Lists (ACLs) and Capabilities.
During the early ’90s, IRIX was a leader in implementing Symmetric Multi-Processing (SMP), supporting configurations ranging from a single CPU up to more than a thousand processors under a unified system image. Its robust handling of real-time disk operations and graphics input/output made it a preferred platform within fields such as computer animation and scientific visualization throughout the ’90s and early ’00s. It continues to be relevant for certain legacy software applications.
Among Unix systems at its time, IRIX was one of the pioneers to offer a graphical user interface as its primary desktop environment. The IRIX Interactive Desktop utilized the 4Dwm window manager within the X Window System framework, styled using the Motif widget toolkit. Additionally, IRIX originated the now-standardized graphics API OpenGL alongside foundational image processing libraries that influenced modern graphics hardware development.
The operating system employs the MIPSPro compiler suite (formerly known as IDO or IRIS Development Option) based on Open64 technology for both frontend and backend compilation tasks. Multiple compiler versions were released alongside OS updates; the final iteration was version 7.4.4m compatible with versions from 6.5.19 onward. This compiler supports parallel programming under POSIX standards using languages such as C/C++, Fortran 77/90, and Ada. Development tools include the Workshop integrated development environment (IDE), Speedshop for performance profiling, and Performance Co-Pilot.
4Dwm
4Dwm serves as the window manager for the IRIX Interactive Desktop found on Silicon Graphics workstations operating under IRIX. It is based on the Motif Window Manager and employs the Motif widget toolkit layered over the X Window System, which is widely used across various Unix platforms. As one of the earliest graphical user interfaces integrated by default on a Unix system, 4Dwm holds a significant place in desktop environments. Its name stands for "Fourth dimension window manager," and it has no connection to dwm.
Multiple X window managers have emulated the appearance of 4Dwm, such as a dedicated 4Dwm theme available for IceWM and 5Dwm, which is a clone derived from OpenMotif. The 5Dwm variant offers compatibility with both the traditional SGI aesthetic and a refreshed design featuring anti-aliased fonts alongside UTF-8 encoding support.
Features
- Employs a stacking window manager model
- Built upon the Motif widget toolkit
- Application launching facilitated through a menu panel
- Window frames include borders and titlebars
- Titlebar equipped with meta button plus minimize and maximize controls
- Supports theming for interface customization