Openwall GNU/*/Linux (Owl) - a security-enhanced server platform

Openwall GNU/*/Linux (or Owl for short) is a small security-enhanced Linux distribution for servers, appliances, and virtual appliances.
Owl live CDs with remote SSH access are also good for recovering or installing systems (whether with Owl or not). Another secondary use is for operating systems and/or computer security courses, which benefit from the simple structure of Owl and from our inclusion of the complete build environment.

You can read more about the concepts behind Owl (including its features and our approach to security), the architectures we support, the guide on using the Owl build environment, and the installation instructions.

You're encouraged to download Owl or purchase a CD, try it out, and provide your feedback to us via the owl-users mailing list (see below).

Owl 3.0 release has been prepared on December 14, 2010. It uses a RHEL 5.5-based Linux 2.6 / OpenVZ kernel and it has optional OpenVZ container-based virtualization integrated. We've since updated to RHEL 5.9-based Linux/OpenVZ kernels.

When you download the ISOs below, please also download iso.mtree and iso.mtree.sign files from the same directory, verify the signature on the iso.mtree file using the iso.mtree.sign file and the PGP key that you obtain from this website, and verify the SHA-1 digests of the ISOs using the iso.mtree file.

Download latest stable version (release notes; more mirrors are available, donations are expected):

Owl 3.0-stable 2013/04/08 for 32-bit x86 ("i686") - or get it on CD
473908263 bytes (452 MB) .iso.gz (requires at least a 700 MB CD-R)
bootable on Pentium Pro/2/3/4 and Celeron (except for some older Pentium M and Celeron M found in some laptops); Xeon (all kinds); Core, Core 2, and Core i3/i5/i7/i9; Atom; Athlon, Opteron; and many more / all newer x86 CPUs and virtual machines (QEMU, etc.)
(requires PAE, supports NX bit when present)
Owl 3.0-stable 2013/04/08 for x86-64 - or get it on CD
479689312 bytes (458 MB) .iso.gz (requires at least a 700 MB CD-R)
bootable on 64-bit capable machines only (including virtual ones such as QEMU, etc.)

Download latest development snapshot (release notes; requirements are similar to those of Owl 3.0 above, but you need DVD media as these ISOs don't fit on a 700 MB CD-R anymore):

Owl-current 2013/04/08 for 32-bit x86 ("i686") - 567636468 bytes (542 MB) .iso.gz
Owl-current 2013/04/08 for x86-64 - 572582967 bytes (547 MB) .iso.gz

The above images include a live system, installable packages, the installer program, as well as full source code and the build environment - everything!

Owl offers binary- and package-level compatibility for most packages intended for Red Hat Enterprise Linux 4 (RHEL4), CentOS 4, and Fedora Core 3 (FC3). For Owl 4.0, our goal is to provide similar support for RHEL6 packages.

There's a mailing list where you can share your experience with Owl and ask questions. Please be sure to specify an informative message subject whenever you post to the list (that is, something better than "question" or "problem"). To subscribe, enter your e-mail address below or send an empty message to <owl-users-subscribe at lists.openwall.com>. You will be required to confirm your subscription by "replying" to the automated confirmation request that will be sent to you. You will be able to unsubscribe at any time and we will not use your e-mail address for any other purpose or share it with a third party. However, if you post to the list, other subscribers and those viewing the archives may see your address(es) as specified on your message. The list archive is available locally, as well as via Gmane and MARC.

A separate mailing list exists for Owl development discussions (that is, if you want to discuss and contribute to the source code). Its archive is available locally. To subscribe, enter your e-mail address below or send an empty message to <owl-dev-subscribe at lists.openwall.com>.

In addition to the owl-users and owl-dev lists you have the option to direct your comments regarding Owl to us privately via <feedback at cvs.openwall.com>. Potential security issues are to be reported to <security at cvs.openwall.com> and non-security bugs to <bugs at cvs.openwall.com>.

Owl is a registered project with Freecode, Ohloh, and DistroWatch.

Please check out our presentation slides on Owl.

Commercial support for Owl is available, please check out our services. Alternatively, you may support the project with donations.

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