"Open access to academic books is a fast-developing area. This creates an exciting but also challenging environment in which to operate key infrastructures supporting open book publishing. We need to ensure that we are available across the ecosystem to support the needs of libraries, funders, and publishers as well as engage and partner with fellow organisations in projects and community-based activities. This is our raison d’etre, but the diversity and sheer volume of tasks and activities requires human capital. Therefore, it’s been such a privilege to welcome four new staff members to OAPEN in 2023. As a team, we turn our mission into action on a daily basis. An expanding staff requires a robust organisation with appropriate administrative and financial systems, archiving and documentation guidelines, policies for human resources and so on. While establishing these is often invisible work to the outside world, it is essential to ensure an efficient and resilient organisation. During 2023 we managed to put into place many of these organisational building blocks that will enable us to expand our organisation, operations, and engagements in the years to come. Moreover, we have shared publicly how we operate by performing a self-audit against the Principles of Open Scholarly Infrastructure (POSI) – discussed later in this report. All of this would not be possible without the financial support we receive from over 225 libraries around the world. We want to thank all our supporting libraries for their continued financial contributions to our operations! We are truly grateful for the trust that you put in our work and for enabling us to perform it well. Likewise, we are sincerely appreciative of our collaboration with funders and publishers, providing them with services including hosting, distribution, and preservation of open access books. We also want to extend our thanks to our private donors and DOAB sponsors. Finally, we would like to emphasise the importance of our engagement with organisations across the globe where we co-create projects to advance and support open access book publishing. These collaborations enable us to design and innovate solutions beyond state-of-the-art. In this report you will learn about our many achievements in 2023. These have led us to enter 2024 more hopeful and excited than we left 2022. Difficult and interesting challenges lie ahead of us, but through steady operation, innovation, and partnerships we will provide solutions in close dialogue with all our relevant stakeholders." (2023 Stakeholder report, page 4)