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

sum 

        # String.sum

(from ruby core)
---
    str.sum(n=16)   -> integer

---

Returns a basic *n*-bit checksum of the characters in *str*, where *n*
is the optional Integer parameter, defaulting to 16. The result is
simply the sum of the binary value of each byte in *str* modulo `2**n -
1`. This is not a particularly good checksum.

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.