The inclusion of software and algorithms in the scope of patents by the US Patent and Trademark Office has propelled an ongoing debate on the contribution of patents to innovation and economic growth. This book examines the effects of Intellectual Property Rights (IPRs), namely patents and copyrights, on innovation and technical change in information technologies. It provides new insights on the links between markets, technologies and legislation by applying a variety of empirical and analytical methods. The book also explores the success of the Open Source movement to establish an alternative regime for IPRs by illuminating the rationale behind it and illustrating how Open Source can strategically be used by firms. Initially the book analyzes the role of IPRs by building upon the literature on the economics of innovation and technical change and on insights from evolutionary economics - in particular, the role of knowledge in the economy. It then goes on to analyze the evolution of IPR regimes and IPR policies with regards to IT and software technologies and products and elaborates their impact on innovation. Finally, a series of empirical and analytical models are provided to elaborate the balance between monopoly rights (by patent and copyrights) and knowledge disclosure as an input for innovation and technological development. Elad Harison's book will appeal to researchers and academics of law and economics, policymakers such as the European Commission, Patent offices, EPO, OECD, as well as directors and strategic managers in large software companies.