Version 1.3 (Released 24 February 2015) of TAILS.

Tails is a live system that aims to preserve your privacy and anonymity. It helps you to use the Internet anonymously and circumvent censorship almost anywhere you go and on any computer but leaving no trace unless you ask it to explicitly.

It is a complete operating system designed to be used from a DVD, USB stick, or SD card independently of the computer's original operating system. It is Free Software and based on Debian GNU/Linux.

Tails comes with several built-in applications pre-configured with security in mind: web browser, instant messaging client, email client, office suite, image and sound editor, etc.

Official site: https://tails.boum.org/index.en.html
For help with TAILS, a good starting point is https://tails.boum.org/doc/first_steps/index.en.html.

Changes in 1.3
New features
Electrum is an easy to use bitcoin wallet. You can use the Bitcoin Client persistence feature to store your Electrum configuration and wallet. The Tor Browser has additional operating system and data security. This security restricts reads and writes to a limited number of folders. The obfs4 pluggable transport is now available to connect to Tor bridges. Pluggable transports transform the Tor traffic between the client and the bridge to help disguise Tor traffic from censors. Keyringer lets you manage and share secrets using OpenPGP and Git from the command line.

Upgrades and changes
The Mac and Linux manual installation processes no longer require the isohybrid command. Removing the isohybrid command simplifies the installation. The tap-to-click and two-finger scrolling trackpad settings are now enabled by default. This should be more intuitive for Mac users. The Ibus Vietnamese input method is now supported. Improved support for OpenPGP smartcards through the installation of GnuPG 2.

Known issues
The Tor Browser shipped in Tails 1.3 has NoScript version 2.6.9.14 instead of version 2.6.9.15, which is the version used in The Tor Project's own Tor Browser 4.0.4 release.
There are numerous other changes that may not be apparent in the daily operation of a typical user. Technical details of all the changes are listed in the Changelog at https://git-tails.immerda.ch/tails/plain/debian/changelog.