% gem install middleman % gem list middleman *** LOCAL GEMS *** middleman (3.2.2) middleman-core (3.2.2) middleman-sprockets (3.2.0) % middleman -v zsh: command not found: middleman % which middleman middleman not found % gem which middleman /usr/local/Cellar/ruby/2.1.0/lib/ruby/gems/2.1.0/gems/middleman-3.2.2/lib/middleman.rb