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

<= 

        # Module.<=

(from ruby core)
---
    mod <= other   ->  true, false, or nil

---

Returns true if *mod* is a subclass of *other* or is the same as
*other*. Returns `nil` if there's no relationship between the two.
(Think of the relationship in terms of the class definition: "class A <
B" implies "A < B".)

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.