One of the constitutive notions of intellectual property is the public domain. These are the ideas, notions and works that are usable by all where no person can invoke a right to block use by another. I am interested in the mechanics of accessing the public domain and the consequences of the choices that we make about the operational effectiveness of various tools available for controlling access to the public domain. That matters both for the extent of access but also importantly for the scale and scope of competition in the provision of the public domain. This takes us to contract and terms of use; to the core of copyright in what it means to be original and also what it means to copy; to copyright’s periphery in the form of the deposit requirement; to the DMCA and its tools of distant control; and to the Computer Fraud and Abuse Act and its restrictions on accessing materials and objects under local control. With the emergence of major digital scanning projects for works in the public domain, we are at a point of possibly unparalleled practical access to the public domain. But the decisions we make about the tools just described will have a strong effect on the scope of the actual access to the public domain that emerges and in the extent of competition on the provision and use of the public domain. We think of the public domain as open to all and in that sense owned by no one (or owned by all). But that ignores the question of how the public domain is actually accessed. We have many tools that control that access and in that sense, through those tools, we re-establish a shadow control regime for the public domain. And we are at the early stages of architecting competition in digital libraries and one piece of that process will be assessing the mechanisms for controlling access to the public domain. Section I of the paper sketches out the emerging public domain. Section II considers three conceptual questions for structuring use of the public domain focusing on the extent to which the public domain should be viral; on whether we should insist that the public domain be accessed only through the original artifacts embodying it; and on whether private appropriability incentives for distribution of public domain scans match overall social interests. Section III turns to the tools for restricting use of the public domain, to copyright, contract, the DMCA and the CFAA. Each of these matters for access to the public domain and for competition over it. Section IV considers one narrow question regarding the relationship between copyright’s deposit requirement and a truly public public domain, while the last section briefly concludes the paper