In no particular order

+ Java doesn't promise "everything is an object." It has Base Types.

+ Python doesn't make a semantic promise that "everything is an object." Code for

  (3).fizzbuzz => "fizz"

probably needs written in C because built-in types are closed and object literals use the built-in types. "3" cannot be forced to use a subclass of Integer.

At the bottom, '3' is defined in terms of Types (i.e. "Built-in Types") not as an Object.

+ Ruby's semantic promise that "everything is an object" means:

  class Fixnum
    def fizzbuzz()
      if self % 15 == 0
        "fizzbuzz"
      end
      if self % 3 == 0
        "fizz"
      end
      if self % 5 == 0
        "buzz"
      end
      return self
    end
  end

And "3" behaves just like any other object. The "everything is an object" promise means that behavior as an object is a cross-cutting concern (or an aspect).