illumos is a free, open source operating system (OS).
Distinguishing features of illumos include:
- ZFS combined file system and logical volume manager for large storage volumes
- DTrace dynamic tracking framework for troubleshooting kernel and application problems
- Kernel-based virtual machine (KVM) supporting native hardware virtualization on processors with hardware virtualization extensions
- Zones, a low-overhead OS virtualization technology
- Crossbow networking virtualization technology
illumos was developed as a fork of Unix-based OpenSolaris, the open source community-built derivative of the Solaris OS. The project launched in 2010. Major contributors include technologists from Delphix, Joyent, Nexenta Systems, and Pluribus Networks.