Yale selected its vendor partner in a formal process, partly funded by the Commission for Preservation and Access. Following a request for proposal, the Yale Library selected two vendors as finalists to work with Yale staff to generate a detailed analysis of requirements for Project Open Book. Each vendor used the results of the requirements analysis to generate and submit a formal proposal for the entire project. This competitive process not only enabled the Yale Library to select its primary vendor partner but also revealed much about the state of the imaging industry, about the varying, corporate commitments to the markets for imaging technology, and about the varying organizational dynamics through which major companies are responding to and seeking to develop these markets. Project Open Book is focused specifically on the conversion of images from microfilm to digital form. The technology for scanning microfilm is readily available but is changing rapidly. In its project requirements, the Yale Library emphasized features of the technology that affect the technical quality of digital image production and the costs of creating and storing the image library: What levels of digital resolution can be achieved by scanning microfilm? How does variation in the quality of microfilm, particularly in film produced to preservation standards, affect the quality of the digital images? What technologies can an operator effectively and economically apply when scanning film to separate two-up images and to control for and correct image imperfections? How can quality control best be integrated into digitizing work flow that includes document indexing and storage? The actual and expected uses of digital images--storage, browsing, printing, and OCR--help determine the standards for measuring their quality. Browsing is especially important, but the facilities available for readers to browse image documents is perhaps the weakest aspect of imaging technology and most in need of development. As it defined its requirements, the Yale Library concentrated on some fundamental aspects of usability for image documents: Does the system have sufficient flexibility to handle the full range of document types, including monographs, multi-part and multivolume sets, and serials, as well as manuscript collections? What conventions are necessary to identify a document uniquely for storage and retrieval? Where is the database of record for storing bibliographic information about the image document? How are basic internal structures of documents, such as pagination, made accessible to the reader? How are the image documents physically presented on the screen to the reader?