This work asks why the computer software industry of the USA has succeeded so dramatically in world competition when so many other strategic technologies have fallen to foreign suppliers. In this economic analysis, Siwek and Furchtgott-Roth present an examination of international trade in computer software. The authors identify software as one of the fastest growing industries in the United States as measured by value added to gross domestic product, employment and foreign sales. They document the historical importance of US-produced software in both American and foreign markets and they present country-by-country assessments of software markets around the world. Siwek and Furchtgott-Roth identify the principal areas of advantage held by the US software industry and they go on to assess the future prospects of US software in world markets.