This is the GNU/Linux version of the volunteer server component of the Salmon censorship circumvention system.
Salmon is released under the GPLv3.
The Release package comes bundled with SoftEther (https://www.softether.org/), which is released under the GPLv2.
To install from the Release package, extract, and run sudo ./install_salmon.sh. This will install and configure both Salmon and SoftEther.
The installer has been thoroughly tested on Ubuntu 14.04 and 12.04. It should work on any distro that has either update-rc.d or chkconfig, though.