This article examines how closely nanotechnology resembles a general purpose technology (GPT). Using patented nanotechnology inventions during 1975-2006, we test for characteristics of GPTs identified in the prior literature, and find evidence that nanotechnology shows both “pervasive” adoption and “spawning” of follow-on innovation. Offering a methodological contribution, we employ concentration indexes such as the Gini index and Lorenz curve to construct “knowledge dissemination curves” for different technologies, thereby providing evidence that nanotechnology shares relevant characteristics with other GPTs. Using an entirely new dataset, we use three different definitions of a “nanotechnology patent” and calculate patent generality indexes, finding that nanotechnology patents are significantly more likely to be referenced across technology space than are patents in information technology, another widely-adopted GPT. In another contribution, we suggest that innovative materials may demonstrate the characteristics of a GPT, and provide a historical parallel between the advancement of steel technology in the 19th Century with that of nanotechnology in the present day.