gem_kit-release's `gem kit` command takes subcommands from other gems. This gem adds one, `gem kit plugin`, which prints a page explaining how it got there — and that is all it does. It exists to be read. The whole mechanism is a GemKit::Release.plugin block in lib/gem_kit/plugin.rb and a one-line lib/rubygems_plugin.rb that requires it. RubyGems loads the latter on every `gem` invocation, so installing the gem is the whole installation.