This section covers globals, constants, and class variables.
Ref.: WGR Ch. 5, The default object (self), scope, and visibility
$
$:
load path (also $LOAD_PATH
)$*
command-line args (also ARGV
)$$
pid$!
the most recent shell error$HOME/.rvm/src/ruby-1.9.2-*/lib/English.rb
@@
@
vars inside class methods@
@@
class variables/