This chapter discusses the impact that open source software has on our perception and use of intellectual property. The theoretical foundation of the paper is constructionist in that it holds intellectual property to be a social construction that is created and legitimized by narratives. In a first step, the chapter recounts the narratives that are usually found in the literature to justify the creation and protection of intellectual property. The two most important streams of narratives are the utilitarian and the natural rights arguments. In a second step, the paper proceeds to the impact that the use of information and communication technology (ICT) has on the narratives of intellectual property. From there, the chapter progresses to a discussion of the impact of open source software on these narratives. It will be argued that open source software changes our perception of intellectual property because it offers evidence that some of the classical narratives are simplistic. At the same time it will become clear that open source is not a frontal assault on intellectual property because it is partly based on ownership of intellectual artefacts. The conclusion discusses how this change of narratives caused by open source software may reflect on our institutions, laws, and regulations of intellectual property.