This is a Ruby tree! It shows every object from the Ruby Programming Language in a tree format.
# NilClass.to_i (from ruby core) --- nil.to_i -> 0 --- Always returns zero. nil.to_i #=> 0
This is MURDOC! A Ruby documentation browser inspired by Smalltalk-80. It allows you to learn about Ruby by browsing through its class hierarchies, and see any of its methods.