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.
We aim to fix that. Crossref and Wikimedia are launching a new initiative to better integrate scholarly literature in the world’s largest public knowledge space, Wikipedia.
This work will help promote standard links to scholarly references within Wikipedia, which persist over time by ensuring consistent use of DOIs and other citation identifiers in Wikipedia references. Crossref will support the development and maintenance of Wikipedia’s citation tools on Wikipedia. This work will include bug fixes and performance improvements for existing tools, extending the tools to enable Wikipedia contributors to more easily look up and insert DOIs, and providing a “linkback” mechanism that alerts relevant parties when a persistent identifier is used in a Wikipedia reference.
In addition, Crossref is creating the role of Wikimedia Ambassador (modeled after Wikimedian-in-Residence) to act as liaison with the Wikimedia community, promote use of scholarly references on Wikipedia, and educate about DOIs and other scholarly identifiers (ORCIDs, PubMed IDs, DataCite DOIs, etc) across Wikimedia projects.
Starting today, Crossref will be working with Daniel Mietchen to coordinate Crossref’s Wikimedia-related activities. Daniel’s team will be composed of Max Klein and Matt Senate, who will work to enhance Wikimedia citation tools, and will share the role of Wikipedia ambassador with Dorothy Howard.
Since the beginnings of Wikipedia, Daniel Mietchen has worked to integrate scholarly content into Wikimedia projects. He is part of an impressive community of active Wikipedians and developers who have worked extensively on linking Wikipedia articles to the formal literature and other scholarly resources. We’ve been talking to him about this project for nearly a year, and are happy to finally get it off the ground.
-G
]7 Matt, Max and Daniel at #wikimania2014. Photo by Dorothy.
