7-Zip for Linux

If you use Debian or Ubuntu it is in the standard repositories (http://packages.ubuntu.com/trusty/p7zip), so you can install it with as little as:

aptitude install p7zip

Or for the full version that includes archive creation and other format support (http://packages.ubuntu.com/trusty/p7zip-full):

aptitude install p7zip-full

There are no doubt packages for it in the official repositories for most other distributions too, probably with the same package names.

PeaZip - a Linux 7-Zip port; supports all file formats that 7-Zip supports. The GUI of PeaZip is also nicer than 7-Zip's.

Website: Peazip.sourceforge.net
Wikipedia article