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

to_a 

        # Hash.to_a

(from ruby core)
---
    hash.to_a -> new_array

---

Returns a new Array of 2-element Array objects; each nested Array
contains a key-value pair from `self`:
    h = {foo: 0, bar: 1, baz: 2}
    h.to_a # => [[:foo, 0], [:bar, 1], [:baz, 2]]

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.