This is a Ruby tree! It shows every object from the Ruby Programming Language in a tree format.
# Exception.message (from ruby core) --- exception.message -> string --- Returns the result of invoking `exception.to_s`. Normally this returns the exception's message or name.
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.