This is a Ruby tree! It shows every object from the Ruby Programming Language in a tree format.

ancestors 

        # Module.ancestors

(from ruby core)
---
    mod.ancestors -> array

---

Returns a list of modules included/prepended in *mod* (including *mod*
itself).

    module Mod
      include Math
      include Comparable
      prepend Enumerable
    end

    Mod.ancestors        #=> [Enumerable, Mod, Comparable, Math]
    Math.ancestors       #=> [Math]
    Enumerable.ancestors #=> [Enumerable]

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.