Imagine a world in which children would be the rulers and could decide not only the outcome of each and every occurrence, but also dictate the very structure and form. of the environment. In this world, a child's wildest thoughts would become reality limited only by the extent of his or her imagination. While such a world might sound both fantastic and frightening, at least from a logical, adult perspective, it does exist. What's more, it has been in existence for some time and is populated by hundreds of thousands of children who spend hours within its boundaries experimenting and learning. This world is not real, at least not in the traditional sense, but exists within a computer and is generated by an educational programming language called LOGO. Unlike other computer languages and programs that are designed to test children and provide applications that formally dispense information, LOGO allows children, even preschool children to be in total control. Children teach the computer to think and as a result develop and sharpen their own reasoning abilities. LOGO is ______.