Copyleft of Simone 'evilsocket' Margaritelli*.
bettercap is a complete, modular, portable and easily extensible MITM tool and framework with every kind of diagnostic and offensive feature you could need in order to perform a man in the middle attack.
Stable Release ( GEM )
gem install bettercap
From Source
git clone https:/evilsocket/bettercap
cd bettercap
gem build bettercap.gemspec
sudo gem install bettercap*.gem
All dependencies will be automatically installed through the GEM system, in some case you might need to install some system dependency in order to make everything work:
sudo apt-get install ruby-dev libpcap-dev
This should solve issues such as this one.
Please refer to the official website.