Various Forums

JuanDeLemos:
1. Kali Linux
http://distrowatch.com/kali  
http://www.kali.org/ 
http://forums.kali.org/
Kali Linux (formerly known as BackTrack) is a Debian-based distribution with a collection of security and forensics tools. It features timely security updates, support for the ARM architecture, a choice of four popular desktop environments, and seamless upgrades to newer versions.

2. Tails 
http://distrowatch.com/tails 
https://tails.boum.org/ 
https://tails.boum.org/support/index.en.html
https://mailman.boum.org/listinfo/
The Amnesic Incognito Live System (Tails) is a Debian-based live CD/USB with the goal of providing complete Internet anonymity for the user. The product ships with several Internet applications, including web browser, IRC client, mail client and instant messenger, all pre-configured with security in mind and with all traffic anonymised. To achieve this, Incognito uses the Tor network to make Internet traffic very hard to trace.

3. Alpine Linux  
http://distrowatch.com/alpine 
http://www.alpinelinux.org/ 
http://lists.alpinelinux.org/
Alpine Linux is a community developed operating system designed for x86 routers, firewalls, VPNs, VoIP boxes and servers. It was designed with security in mind; it has proactive security features like PaX and SSP that prevent security holes in the software to be exploited. The C library used is musl and the base tools are all in BusyBox. Those are normally found in embedded systems and are smaller than the tools found in GNU/Linux systems.

4. BackBox Linux  
http://distrowatch.com/backbox
http://www.backbox.org/
http://groups.google.com/group/backbox-linux
http://forum.backbox.org/
BackBox Linux is an Ubuntu-based distribution developed to perform penetration tests and security assessments. It is designed to be fast and easy to use. It provides a minimal yet complete desktop environment, thanks to its own software repositories, which are always updated to the latest stable versions of the most often used and best-known ethical hacking tools.

5. ClearOS  
http://distrowatch.com/clearos 
https://clearos.com/ 
https://clearos.com/clearfoundation/social/community
ClearOS Enterprise is a server, network, and gateway platform designed for small businesses and distributed enterprise environments. ClearOS Enterprise is based upon ClearOS Core which is a rebuild of Red Hat Enterprise Linux. The distribution is flexible and includes an extensive list of features and integrated services which can be configured through a web-based interface. Some of the tools found in ClearOS Enterprise include anti-virus, anti-spam, VPN, content filtering, bandwidth manager, file services, SMTP services, print services, SSL certification, and web services. ClearOS includes a marketplace which simplifies the installation of software including 3rd party modules. The distribution is provided as a free download, inclusive of basic OS updates with free registration.

6. Wifislax  
http://distrowatch.com/wifislax 
http://www.wifislax.com/ 
http://foro.seguridadwireless.net/live-wifislax/
Wifislax is a Slackware-based live CD containing a variety of security and forensics tools. The distribution's main claim to fame is the integration of various unofficial network drivers into the Linux kernel, thus providing out-of-the-box support for a large number of wired and wireless network cards.

7. OpenBSD  
http://distrowatch.com/openbsd  
http://www.openbsd.org/
http://www.openbsd.org/mail.html 
http://www.openbsd.org/ftp.html   
http://www.openbsd.org/report.html 
The OpenBSD project produces a free, multi-platform BSD 4.4-based UNIX-like operating system. Its efforts emphasize portability, standardisation, correctness, proactive security and integrated cryptography. The project also develops the widely-used and popular OpenSSH (OpenBSD Secure Shell) software, which provides encrypted communication sessions over a computer network using the SSH protocol.

8. BlackArch Linux  
http://distrowatch.com/blackarch 
http://blackarch.org/ 
http://blackarch.org/guide.html 
http://blackarch.org/download.html 
https://github.com/BlackArch/blackarch/issues 
BlackArch Linux is an Arch Linux-based distribution designed for penetration testers and security researchers. It is supplied as a live DVD image that comes with several lightweight window managers, including Fluxbox, Openbox, Awesome and spectrwm. It ships with over a thousand specialist tools for penetration testing and forensic analysis.

9. Qubes OS  
http://distrowatch.com/qubes 
http://qubes-os.org/ 
http://groups.google.com/group/qubes-devel 
http://wiki.qubes-os.org/ 
http://qubes-os.org/Screenshots.html 
https://wiki.qubes-os.org/wiki/QubesDownloads
Qubes OS is a security-oriented, Fedora-based desktop Linux distribution whose main concept is "security by isolation" by using domains implemented as lightweight Xen virtual machines. It attempts to combine two contradictory goals: how to make the isolation between domains as strong as possible, mainly due to clever architecture that minimises the amount of trusted code, and how to make this isolation as seamless and easy as possible.

10. Pentoo  
http://distrowatch.com/pentoo 
http://www.pentoo.ch/ 
http://forums.pentoo.ch/ 
http://www.pentoo.ch/docs/ 
http://www.pentoo.ch/download/ 
https://code.google.com/p/pentoo/issues/list
Pentoo is a Gentoo-based Linux live CD with a selection of applications and tools designed to perform penetration testing.

11. Zentyal Server  
http://distrowatch.com/zentyal 
http://www.zentyal.org/ 
http://lists.zentyal.org/ 
http://forum.zentyal.org/ 
http://wiki.zentyal.org/ 
http://trac.zentyal.org/screenshots 
http://www.zentyal.org/downloads/ 
http://tracker.zentyal.org/ 
Zentyal Server (formerly eBox Platform) is a unified network server that offers easy and efficient computer network administration for small and medium-size businesses. It can act as a gateway, an infrastructure manager, a unified threat manager, an office server, a unified communication server or a combination of them. These functionalities are tightly integrated, automating most tasks, avoiding mistakes and saving time for system administrators. Zentyal is released under the GNU General Public License (GPL) and runs on top of Ubuntu.

12. Openwall GNU/*/Linux 
http://distrowatch.com/openwall 
http://www.openwall.com 
http://www.openwall.com/lists/ 
http://www.openwall.com/Owl/INSTALL.shtml 
http://openwall.info/wiki/  
http://www.openwall.com/Owl/screenshots 
http://www.openwall.com/Owl/DOWNLOAD.shtml
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 the inclusion of the complete build environment.

13. Lightweight Portable Security  
http://distrowatch.com/lps 
http://www.spi.dod.mil/lipose.htm 
http://www.spi.dod.mil/docs/lpsmanual.pdf  
http://www.spi.dod.mil/lipose.htm 
Lightweight Portable Security (LPS) is a Linux-based live CD with a goal of allowing users to work on a computer without the risk of exposing their credentials and private data to malware, key loggers and other Internet-era ills. It includes a minimal set of applications and utilities, such as the Firefox web browser or an encryption wizard for encrypting and decrypting personal files. The live CD is a product produced by the United States of America's Department of Defence and is part of that organization's Software Protection Initiative.

14. Network Security Toolkit  
http://distrowatch.com/nst 
http://www.networksecuritytoolkit.org/ 
http://sourceforge.net/forum/forum.php?forum_id=361524 
http://wiki.networksecuritytoolkit.org/ 
http://nst.sourceforge.net/nst/screenshots/index.html 
http://sourceforge.net/projects/nst/files/ 
http://sourceforge.net/apps/trac/nst/report 
Network Security Toolkit (NST) is a bootable live CD based on Fedora Core. The toolkit was designed to provide easy access to best-of-breed open source network security applications and should run on most x86 platforms. The main intent of developing this toolkit was to provide the network security administrator with a comprehensive set of open source network security tools. What we find rather fascinating with NST is that we can transform most x86 systems (Pentium II and above) into a system designed for network traffic analysis, intrusion detection, network packet generation, wireless network monitoring, a virtual system service server, or a sophisticated network/host scanner.