Crossref was created back in 2000 by 12 forward-thinking scholarly publishers from North America and Europe, and by 2002, these members had registered 4 million DOI records. At the time of writing, we have over 23,600 members in 164 different countries. Half of our members are based in Asia, and 35% are universities or scholar-led. These members have registered over 176 million open metadata records with DOIs (as of today). What a difference 25 years makes!
In our 25th anniversary year, I thought it would be time to take a look at how we got here. And so—hold tight—we’re going to go on an adventure through space and time1, stopping every 5 years through Crossref history to check in on our members. And we’re going to see some really interesting changes over the years.
The Frankfurt Book Fair is the largest book fair in the world, and therefore a key event on our calendar. Held annually in Frankfurt, Germany, the 77th Frankfurt Book Fair (October 15–19, 2025) saw 118,000 trade visitors and 120,000 private visitors from 131 countries. The Crossref booth was located, as usual, in Hall 4.0 where all the stands with information about academic publishing can be found. Four Crossref colleagues attended the Book Fair this year, and in this blog post, you can read more about their meetings, experiences, and plans.
TL;DR. Metadata Manager will be retired at the end of 2025. Over the past four years, we have been developing a new helper tool to replace it, and that tool has now reached a stage of maturity that means we will be able to switch off Metadata Manager by the end of the year.
Our REST API makes all of the metadata we hold publicly available. It receives the majority of our API traffic, with around 1 billion hits per month. It’s one of the key ways that we fulfil our mission to make research objects easy to find, cite, link, assess, and reuse. From 1 December 2025, we will be revising the rate limits for the public and polite pools of the REST API to ensure that we can maintain a stable and reliable system, and that metadata is freely available to everyone.
22 June 2021, London, UK and Boston, MA, USA — The future of global open access publishing received a boost today with the signing of a Memorandum of Understanding between the Directory of Open Access Journals (DOAJ) and Crossref. The MOU formalizes an already strong partnership between the two organisations and furthers their shared pursuit of an open scholarly communications ecosystem that is inclusive of emerging publishing communities.
Both organisations aim to encourage the dissemination and use of scholarly research using open infrastructure, online technologies, regional and international networks, and community partners - all supporting local institutional capacity and sustainability around the world.
“DOAJ is delighted to be formalizing today’s agreement with Crossref, an organisation we are already closely aligned with. Together we stand a greater chance of encouraging an open, fair, and fully inclusive future for scholarly publishing,” said Lars Bjørnshauge, DOAJ Founder and Managing Director.
The agreement will enable content from journals indexed on DOAJ to be more easily identified through the use of Crossref metadata. The MOU also covers the exchange of a variety of services and information and greater coordination of technical and strategic requirements between DOAJ and Crossref. Included too is the development of outreach and training materials, coordination of service and feature development, as well as research studies to explore the overlaps and gaps in the journals and metadata covered by each organisation.
“As academic-led journals continue to grow in number and geographic reach, it’s important we support this community more effectively. Our partnership with DOAJ means we can share strategies, data, and resources in order to lower barriers for emerging publishers around the world,” said Ginny Hendricks, Crossref’s Director of Member & Community Outreach.
About DOAJ
DOAJ is a community curated online directory that indexes and provides access to high quality, open access, peer reviewed journals. DOAJ deploys more than one hundred carefully selected volunteers from among the community of library and other academic disciplines to assist in the curation of open access journals. This independent database contains over 15,000 peer-reviewed open access journals covering all areas of science, technology, medicine, social sciences, arts and humanities. DOAJ is financially supported worldwide by libraries, publishers and other like-minded organisations. DOAJ services (including the evaluation of journals) are free for all, and all data provided by DOAJ are harvestable via OAI/PMH and the API. See doaj.org for more information.
About Crossref
Crossref makes research objects easy to find, cite, link, assess, and reuse. We’re a not-for-profit membership organisation that exists to make scholarly communications better. We rally the community; tag and share metadata; run an open infrastructure; play with technology; and make tools and services—all to help put research in context. Visit crossref.org for further information.
