Conclusions 16 CHAPTER For those readers who are accustomed to various sorts of knowledge modeling, the Semantic Web looks familiar. The notions of classes, subclasses, properties, and instances have been the mainstay of knowledge modeling and object systems modeling for decades. It is not uncommon to hear a veteran of one of these technologies look at the Semantic Web and mutter, "Same old, same old," indicating that there is nothing new going on here and that everything in the Semantic Web has already been done under some other name elsewhere. As the old saying goes, "There is nothing new under the sun," and to the extent that the saying is correct, so are these folks when they speak of the Semantic Web. The modeling structures we have examined in this book do have a strong connection to a heritage of knowledge modeling languages. But there is something new that has come along since the early days of expert systems and object- oriented programming; something that has had a far more revolutionizing effect on culture, business, commerce, education, and society than any expert system designer ever dreamed of. It is something so revolutionary that it is often compared in cultural significance to the invention of the printing press.