This presentation discusses open access book publishing. The OAPEN Foundation aims to increase discoverability and promote trust in open access books. It hosts over 25,000 peer-reviewed open access books through the OAPEN Library and indexes over 60,000 books through the Directory of Open Access Books. The Peer Review Information Service for Monographs works to increase transparency around peer review processes for academic books. The Open Access Books toolkit provides resources for authors on open access publishing.