Open access book publishing is a model that makes long-form research accessible to global audiences. The problem is that the number of books being made available as open access is only increasing, making it harder for specific books to be discovered amongst the vast number of online libraries. That’s where the Directory of Open Access Books (DOAB) seeks to help researchers and general readers find the books they need.

In this article, we’ll explain what DOAB is, how it works and why it matters, and why it’s important for publishers to support this online discovery service.

What is the Directory of Open Access Books?

The Directory of Open Access Books was launched in 2012 by the OAPEN foundation, a not-for-profit foundation supporting open access infrastructure within scholarly book publishing.

DOAB is an open source, community-led discovery service that indexes and provides access to peer-reviewed academic books. Its primary purpose is to increase the discoverability of open access books.

Importantly, all of DOAB’s services are free of charge and all data freely available. But what makes DOAB possible?

How it works

Open access book publishers are invited to provide the metadata of their scholarly publications to the Directory of Open Access Books. Metadata refers to key information about the book, such as title, author, publisher, DOIs, ISBNs, subject and keywords, licensing, and peer review details.

This metadata is made harvestable by DOAB to maximise dissemination, visibility, and impact. Metadata helps users discover scholarly content much more easily than if they were searching through traditional search engines or various publisher libraries. Furthermore, aaggregators can integrate the records into their commercial services and libraries can integrate the directory into their online catalogues, helping scholars and students to discover books.

The discovery service also ensures scholarly integrity through what they call the DOAB Trusted Platform Network. This is a collaboration that allows publishers who index their open access books with any platforms recognised by the DOAB Trusted Platform Network to request these platforms to verify which of their open access books meet the DOAB criteria. As part of this collaboration, verified books will be automatically listed and discoverable in DOAB.

Why it matters

Whether a book is made available physically or via open access, the mode of access is not a guarantee that the book has been peer reviewed. Yet maintaining scholarly integrity is vital, especially in a digital age struggling with issues of misinformation and generative AI.

The Directory of Open Access Books matters because trust matters in academic publishing. Librarians, researchers, and students want to know that the books they are engaging with are peer reviewed. This is particularly pertinent given that there is a common myth that open access books are not reviewed. They also want to know that the publishers behind these books can be trusted, ensure long-term accessibility, and use open access licenses like creative commons.

DOAB centralises all the information necessary for users to validate scholarly long-form content. It focuses on cataloguing and increasing the visibility of peer-reviewed books, therefore making research, critical engagement, and reuse of academic material much simpler.

Demand for open access books also seems to be increasing, further highlighting the necessity of a service like DOAB. Path to Open, an initiative launched by JSTOR to “expand global access to peer-reviewed academic books”, has recently reported a 30% increase in item requests for 100 titles flipped to open access so far in 2026, compared with the previous year. This is a positive trend that shows that attitudes towards open access books are shifting in the right direction.

MDPI Books and DOAB

MDPI Books is a bronze sponsor of DOAB, helping sustain and develop the platform and its services. DOAB indexes our peer-reviewed open access books, allowing researchers to find them through a central database.

This kind of reciprocal partnership in open access book publishing is important to nurture. Whether through indexing their metadata, talking about these services, or building partnerships, publishers need to support community-driven services like DOAB that strengthen open access infrastructure and scholarly integrity in the long term.

Maintaining access to free scholarly books is paramount to the aims of both MDPI Books and DOAB. To find free open access books online, visit our library today. You can also locate and read MDPI books for free using DOAB’s database.