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What is illumos?

To quote the illumos Developer's Guide:

illumos is a consolidation of software that forms the core of an Operating System. It includes the kernel, device drivers, core system libraries, and utilities. It is the home of many technologies including ZFS, DTrace, Zones, CTF, FMA, and more. We pride ourselves on having a stable, highly observable, and technologically different system. In addition, illumos traces it roots back through Sun Microsystems to the original releases of UNIX and BSD.

illumos itself does not offer an OS distribution -- rather, it is the core from which distributions can be created. In this sense, illumos is similar to a BSD source tree, or Linux's

Please see the history page for more information about the origins of illumos.


illumos is available under the Common Development and Distribution License (CDDL).

Community Values

  • Empathy for users as a core engineering value
  • Maintaining code quality through peer review

Technology Features

The following are shared development tenets and features for distributions utilizing illumos:

  • Stability
  • SMP support for many CPUs
  • Security facilities like Role-based Access Control (RBAC) and Privileges
  • Multi-tenancy with Zones
  • Deep system introspection with DTrace
  • A unified Fault Management Architecture (FMA) for monitoring hardware
  • Network virtualization with Crossbow
  • Hardware virtualization with KVM
  • Excellent manual pages
  • Source code for the entire system

For more in-depth descriptions, please see the features page.

Uses for illumos

While it can be and is used in nearly any situation where a UNIX-type server is needed, illumos excels at storage applications, large multi-tenant systems, and other cloud-centric uses.

Have a look at who is using illumos to see what illumos technologies are being used for!

Supported hardware platforms

illumos currently supports 64-bit x86 hardware from Intel and AMD.

To determine if a specific piece of hardware will work with illumos, please refer to the Hardware Compatibility List.

For pre-defined builds of server-grade hardware, you may also refer to the Triton Engineering Manufacturing database.

illumos Development Model

Please refer to the illumos Developer's Guide, as well as the Building illumos and contribution sections of this documentation.

Contributing to illumos

Please see the community and contribution guides if you'd like to participate in the project.

Third Party Software

illumos does not itself ship third party software, or contain software like webservers and so forth.

Distributions include their own package management.