This is a Ruby tree! It shows every object from the Ruby Programming Language in a tree format.
# IO.printf (from ruby core) --- ios.printf(format_string [, obj, ...]) -> nil --- Formats and writes to *ios*, converting parameters under control of the format string. See Kernel#sprintf for details.
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.