Tails
The Amnesic Incognito Live System (Tails) is a Debian-based live DVD/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.
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Gentoo Linux
Gentoo Linux is a versatile and fast, completely free Linux distribution geared towards developers and network professionals. Unlike other distros, Gentoo Linux has an advanced package management system called Portage.