[millennia]

The CoffeeScript gem is included by default in new rails installs, and some js.coffee files are created, so you'd have to explicitly remove it - most people won't bother even if they are writing most of their js without it. The following gems are included by default, which perhaps makes the usage in these apps (done in a hurry) not very surprising:

  gem 'sass-rails'
  gem 'coffee-rails'
  gem 'jquery-rails'