UNIX System V Release 4
AT&T & Sun Microsystems. Still developed
The landmark unified Unix standard combining AT&T System V, SunOS, BSD, and Xenix technologies, forming the technical foundation for SunOS 5.
illumos & Solaris as of Nov 2026
Rank 25 illumos distributions, Solaris systems, and historic Unix releases from 21 makers, from OmniOS CE, OpenIndiana, SmartOS, Tribblix, and Oxide Helios to Oracle Solaris 11, OpenSolaris, and SVR4. Filter by filesystem, packaging, and use cases, inspect detailed spec sheets, and drag, tap, or use the keyboard. Your rankings save locally in your browser and can be shared as a link or exported as an image.
Drag systems into tiers, or tap one and then a tier. Keyboard: focus a system, press 1–6 to rank it and 0 to unrank, or Enter then the arrow keys to move it. Ctrl+Z undoes.
Trace modern illumos and Solaris distributions back to System V Release 4 roots, and hover a logo for details.
12 of the 25 systems descend from the open-source illumos kernel, 9 from the original Sun OpenSolaris project, and 3 from the Solaris and SunOS line.
AT&T & Sun Microsystems. Still developed
The landmark unified Unix standard combining AT&T System V, SunOS, BSD, and Xenix technologies, forming the technical foundation for SunOS 5.
Sun Microsystems & Oracle. Still developed
Sun’s premier commercial Unix operating system, introducing symmetric multiprocessing (SMP), ZFS, DTrace, and Solaris Containers / Zones.
Sun Microsystems. Retired
Sun’s pioneering initiative to open-source the Solaris ON codebase under the CDDL, introducing IPS packages and inspiring community distributions worldwide.
Garrett D’Amore & illumos Community. Still developed
The fully open-source continuation and kernel fork of OpenSolaris, maintaining ZFS, DTrace, Zones, and Bhyve/KVM virtualization across modern hardware.
Dashed logos mark systems that grew out of that base before moving on.