Unleashed is an operating system fork of illumos (see why), which itself is a derivative of OpenSolaris and therefore has its roots in UNIX System V Release 4.

It is intended as a modern Unix operating system for developers by developers; it comes with ZFS, DTrace, Crossbow and more.

Note: Development on Unleashed ceased immediately after the 1.4 release. For more information on why, see the release notes.

Download & Installation

The only systems currently supported are amd64-based computers and virtual machines.

Unleashed is being maintained as a hobby, and as such we cannot guarantee releasing security or other patches. Run it in production at your own risk.

IRC & Mailing Lists

You can find us in #unleashed on Freenode.

We have two mailing lists: one for general development discussions (subscribe, archives) and one with commit notifications (subscribe, archives).

Security sensitive information can be sent to jeffpc@josefsipek.net. If you wish, you may encrypt your message with Jeff's PGP key.


If you want to make Unleashed better, send us a patch, an email, or join us on IRC! We don't have mandatory code review or any other convoluted processes; just show us the code.

The source code itself is split across several git repositories:

The steps to build each vary, but they are documented in each repository's top-level README.


Aside from the typical set of man pages, there is a docs directory in the main git repository.