This paper introduces the Open Book Collective, a new member-governed charity devoted to supporting the production and dissemination of Open Access Books from small-to-medium publishers. The OBC is committed to supporting equity and bibliodiversity in OA publishing. This means supporting small-to-medium publishers in diverse geographic and linguistic settings, while making content produced by OBC members accessible to a wider range of authors and institutions. Our model supports publishers in moving away from Book Processing Charges, which can re-entrench the inequalities already inherent in academia, leading to a stultification of fields. The OBC positions itself as an alternative to the monopolies of a handful of dominant publishing houses in academia across the globe. Our membership, comprised of librarians, publishers, OA service providers, librarians, and other supporters works collectively bring about a fairer and more sustainable model of open book publishing. From our development research in collaboration with our library colleagues, we know that many libraries and institutions wish to support OA Books and have budget set aside to do so. But a confusing array of options, lack of easily readable metadata, and the varied workflow of OA publishers makes it difficult and time-consuming for libraries and their institutions to know where to invest their support. The OBC platform offers a fast and simple way for libraries to compare publishers’ catalogues, packages, business plans, and values, allowing the creation of pre-made or bespoke subscription packages before generating a quotation. The OBC then manages the subscription, and delivers benefits to libraries including maximally readable metadata, easy integration into existing workflows, and a guarantee of quality via the vetting and application process our publisher members must go through. We assess all membership packages on the platform, to ensure they are priced fairly and that funding will support high quality OA publishing and distribution.