Digital resources in the Social Sciences and Humanities OpenEdition Our platforms OpenEdition Books OpenEdition Journals Hypotheses Calenda Libraries OpenEdition Freemium Follow us

Building, Maintaining, Listening: OpenCitations’ 2025

Looking back at 2025, OpenCitations experienced a year defined by both visible engagement and foundational work where, while the technical aspects and collaborative workflows were strengthened behind the scenes, many accomplishments were shared openly with (and for the benefit of) the community. What follows, therefore, is not just a list of milestones but a narrative of alignment between the technical architecture, outreach, and collaboration.

Embracing and managing growth

One of the central challenges for OpenCitations in 2025 was how to grow without losing quality. Over the year, four major data dumps were released: two for OpenCitations Meta and two for OpenCitations Index. The last 2025 Index dump, released in July, surpassed 2.2 billion citation records. Although we acknowledge that there were fewer dumps than usual in terms of frequency, we justify this slower pace by the fact that over the last two years the technical team has committed to a comprehensive infrastructure redesign, focusing particularly on data refinement and quality improvement. The goal was to provide fewer dumps, but with higher quality. Now that the mechanisms are well-established, we expect to increase the frequency of dumps in 2026.

Working to include new data sources

Many of the advances of 2025 emerged not from isolated development but from collaboration. Significant effort went into improving how citation data enters OpenCitations in the first place. Collaborations with external projects explored new ways to make the ingestion of citation data more efficient, potentially widening the range of sources that can contribute to the open citation ecosystem.

In particular, PKP, OpenCitations, and TIB have started implementing a workflow in OJS. TIB has created a plugin for OJS to enable ingestion of OJS citations directly into OpenCitations. During 2025, OpenCitations has been working on crowdsourcing an automatic workflow to ingest these citations into its collections directly.

Similarly, collaboration with the Matilda project, a bibliographic and bibliometric platform for open science, focused on validating tabular bibliographic data before ingestion, with the perspective of including Matilda citations as a future source of OpenCitations.

Re-engineering for the living will

Part of the 2025 work took place out of sight. The OpenCitations technical team undertook a comprehensive redesign of the infrastructure architecture, moving toward a microservices-based approach supported by Infrastructure as Code (IaC).

The redesign was guided by the long-term perspective of improving scalability and reliability, reducing operational friction, and ensuring that the infrastructure could move, adapt, and survive beyond any single deployment context. The result is an infrastructure that can be redeployed or transferred with minimal overhead. In this context, in light of the meaningful progress made in ensuring the “living will” of the infrastructure, in 2026 we plan to update our compliance assessment with the Principles of Open Scholarly Infrastructure, currently at version 2.0, released in October 2025. This version clarifies and expands on governance, sustainability and insurance principles for open scholarly infrastructures, including commitments to stakeholder governance, open licensing, clear data availability and interoperability to ensure resilience and continuity.

At the same time, attention turned to the question of quality as an ongoing practice. We successfully tested HERITRACE, a semantic data-curation tool developed for the GLAM sector, enabling intuitive editing of bibliographic data along with provenance and change tracking (announced at the end of 2024), in a small pilot, standing out from existing platforms thanks to its ease of use, strong provenance management, and high customisation. Within OpenCitations, HERITRACE will allow users to curate bibliographic and citation metadata, improving overall data quality.

OpenCitations’ window display completed

In early 2025, OpenCitations also turned its attention outward, introducing a renewed visual identity, including a new logo. This was not simply an aesthetic update, but part of a broader effort to better communicate OpenCitations’ values: openness, transparency, and community.

The website redesign followed the same logic. With a cleaner structure and clearer navigation, the site now offers faster access to core services, while also making OpenCitations itself more visible. It also places greater emphasis on OpenCitations’ community-driven nature, with expanded sections highlighting the organisation’s mission, values, team, membership programme, partners, and international collaborations, making it easier for all users to engage with and understand OpenCitations’ work.

Talking about Open Research Information at WOOC2025

In May 2025, OpenCitations hosted the Workshop on Open Citations and Open Scholarly Metadata (WOOC) in Bologna. Over two days, researchers, publishers, funders, policy-makers, and infrastructure providers came together to discuss open access to research information.

The workshop combined strategic discussion, such as the Bologna Meeting on Open Research Information, with community presentations, posters, and invited talks, creating a space where policy, infrastructure, and scholarly practice could meet. As in previous editions, WOOC served not only as a venue for sharing work, but as a space for coordination, alignment, and long-term thinking around open scholarly metadata.

From audience to co-creation

As part of the effort dedicated to improving community awareness of OpenCitations through dedicated outreach initiatives, in October, we launched our own Newsletter, creating a regular channel for sharing updates, technical developments, and community stories, helping to keep a diverse international audience informed and connected.

In parallel, OpenCitations launched a Community Survey to actively gather feedback from users, partners, and the research community as a whole. Rather than assuming needs or priorities, the survey explicitly invited critique, uncertainty, and suggestion, treating community members not as end users, but as co-creators of OpenCitations’ future. The responses will directly inform future development, reinforcing the idea of OpenCitations as a genuinely community-driven infrastructure.

What’s next?

If 2025 can be characterised by a single idea, it is continuity. Rather than chasing novelty, OpenCitations invested in making its data more reliable, its infrastructure more resilient, and its relationship with the community stronger.

These foundations matter. They enable growth without fragility, collaboration without dependency, and openness without compromise. As OpenCitations moves forward, the work of 2025 will remain present: not always visible, but deeply embedded in how open citation data is produced, shared, and sustained.

Wheels Are in Motion: OpenCitations’ progress in 2024

January is a strange month. After the festive whirl of December’s gatherings, it quickly shifts into the hustle and bustle of the new year’s commitments and the work that follows the holidays. For us at OpenCitations, however, it has become a tradition to take a moment at the end of this month to pause after the first hectic weeks of the year. This time allows us to reflect on the achievements of the past year and plan for the future with a clearer mind.  

2024 has been a transitional year, one where we’ve worked “in the shadows”, focusing on a series of behind-the-scenes improvements that will transform the OpenCitations experience for our users and services. Over the past few years, we have gathered valuable feedback from our community and have taken it to heart, using it to inform the enhancements to our infrastructure. These changes will be rolled out in the coming months of 2025, and we are excited to share a glimpse of what’s to come.

1. Strengthening the Foundations of the Technical Infrastructure

We closed out 2023 by announcing the redesign of our technical infrastructure, a crucial step for better managing OpenCitations’ data sources. This shift was necessary to enhance the efficiency of our processes and ensure scalability for the future. In particular, in recent months, our development team has been focused on addressing issues within OpenCitations Meta, to enable to set up again the usual bimonthly updates from one of our main data sources (i.e. Crossref). This work is essential to guarantee the timely release of the OpenCitations Index. 

We were happy to announce the July 2024 release of the Index, containing more than 2 billion citations, but we are now working to ensure that the release frequency is consistent throughout 2025. Our focus will be on maintaining a steady pace, ensuring regular updates, and improving the overall reliability of our data.

2.A Tool for Data Curation: HERITRACE

In addition to infrastructure improvements, we have been developing a new tool designed to streamline data curation: HERITRACE. This semantic data management system is tailored specifically for the GLAM (Galleries, Libraries, Archives, and Museums) sector. HERITRACE serves as an editor for curating bibliographic data, allowing users to track provenance and monitor changes over time. 

It has been tested in a small-scale project with a specific dataset, and early results have been promising. HERITRACE is designed to be user-friendly, offering non-technical users a seamless experience while providing an efficient administrative interface for technical staff. In comparison to other established platforms such as OmekaS, Semantic MediaWiki, Research Space, and CLEF, it stands out for its ease of use, provenance management, change tracking, and customization options. 

HERITRACE is built upon SHACL for data modeling and integrates the OpenCitations Data Model (OCDM) for tracking provenance and changes. Looking ahead, we plan to expand its capabilities with the integration of a robust authentication system and broader data compatibility through the RDF Mapping Language (RML), making it an even more powerful tool for digital heritage management. 

In the context of OpenCitations, the goal is to use HERITRACE to enable curating bibliographic metadata and citation data by expert users (e.g. librarians), aiming at increasing the quality of the data OpenCitations provides. 

In the video below, our developer Arcangelo Massari provides a quick overview and tutorial of HERITRACE:

 

3.New and Ongoing Collaborations

During 2024, we have honoured the aspects of our mission statement describing community engagement as a core point in OpenCitations’ activities. These partnerships are vital to advancing OpenCitations’ purposes and goals, and we look forward to continuing the collective work into 2025. In particular, we expanded the network of partnerships and released some outcomes of previous collaborations:  

  • Our project within the European Research Council (2023-2024) dedicated to the mapping of metadata collections between OpenCitations Meta and OpenAlex, has concluded. The full analysis is presented in the following article involving OpenCitations Developer Elia Rizzetto:  

Rizzetto, E.; Peroni, S., Mapping bibliographic metadata collections: the case of OpenCitations Meta and OpenAlex, in: CEUR Workshop Proceedings, CEUR-WS, «CEUR WORKSHOP PROCEEDINGS», 2024, 3643, pp. 155 – 168 (Proceedings of the 20th Conference on Information and Research Science Connecting to Digital and Library Science, IRCDL 2024, Bressanone – Brixen, Italia, 2024)  

  • January 2025 has formally marked the beginning of two new exciting projects in collaboration with OPERAS and other institutional and industrial partners, building upon our previous work together within the GraspOS Project. During 2024, it’s been inspiring being involved in the work packages of the project, where we have kept collaborating with our colleagues from OpenAIRE. Also, GraspOS is doing a terrific job in the promotion of the news and initiatives of its community, through its newsletter, and its blog (where you can also find an exclusive interview with our Director and one with our Head of Comms – hi, it’s me!), so we suggest you subscribe and follow if interested in the theme of Open Science and Responsible Research Assessment.
  • In April, we were included in Infra Finder, a tool developed by Invest in Open Infrastructure to foster discovery, adoption, and investment in open infrastructure services. The intuitive interface and usability make Infra Finder a helpful tool that could make OpenCitations and other infrastructure services more visible to a wider and diverse community. 
  • We continued our participation in the SCOSS Family, the community of practice gathering the Infrastructures from SCOSS six pledging rounds, and we are now part of the internal working groups aimed at exploring ways of collaboration, sharing resources, creating impact and contributing to creating a stronger open ecosystem.  
  • Lastly, OpenCitations is proud to be one of the supporters of the Barcelona Declaration, a key initiative launched in April 2024 aimed at fostering open access to scholarly information and advancing the principles of open science. This aligns perfectly with OpenCitations’ mission to promote transparency, accessibility, and collaboration in scholarly communication. By supporting the Barcelona Declaration, we reaffirm our commitment to the shared values of openness, inclusivity, and the democratization of knowledge, all of which are integral to creating a more equitable and accessible academic landscape for researchers, institutions, and the global community.  

4.Welcome and Farewell

Alongside the growth of our network, the OpenCitations team has also expanded, now counting 11 collaborators, including Research Fellows and PhD students, with the addition of Ivan Heibi as Chief Technology Officer (CTO) and Mario Petrella as Systems Administrator. 

Besides the enrichment brought in by our new colleagues, 2024 also brought a great loss. The founder and director of OpenCitations, David Shotton, passed away in May, leaving not only an institutional but, most of all, a human void, as a mentor and guide. We wanted to remember him in this blog post, which aims to serve as a virtual wall of tribute, constantly evolving, where anyone wishing to share a thought for David can do so by sending an email to comms@opencitations.net.  

5.Renewal of the International Advisory Board for OpenCitations

After four years of prolific collaboration, the end of 2024 also marked the conclusion of our International Advisory Board’s first term. We’d like to extend our deepest gratitude to the former members for their invaluable insights and guidance throughout their tenure. Looking ahead, we are thrilled of the new members who have decided to put their expertise at OpenCitations’ service, and we can’t wait to begin working closely with them in 2025.

6.Some Spoilers for 2025

As we close out this year’s reflections, we’re also looking ahead to 2025. In this upcoming year, we will begin to see the fruits of our work from 2024. We are committed to continuously improving our offerings and services for our users and the community that supports us. We exist because of them, and we are here to serve their needs. 

In the coming weeks, you will also notice some exciting changes: OpenCitations will be undergoing a rebranding, along with updates designed to make our virtual presence more engaging and user-friendly. We’ve heard feedback about how challenging it can sometimes be to navigate our information, and we’re eager to make improvements that will help our users find what they need more easily. 

Finally, we invite all our readers to participate in the 5th Workshop on Open Citations and Open Scholarly Metadata (WOOC), which will be held in Bologna on May 28-29, 2025. WOOC aims to gather anyone interested in the widespread adoption of practices for creation, sharing, reuse and improvement of open scholarly metadata. This year’s edition of the workshop will be a special one, gravitating around the following theme: “Open Access of Research Information”. 

In particular, the first day will be dedicated to the Bologna Meeting on Open Research Information, to encourage discussion between the signatories and supporters of the Barcelona Declaration and other interested bodies and collaboratively orient the common roadmap, thus allowing the articulation of the outcomes that have recently been discussed during the Paris Conference on Open Research Information. 

The second day will be dedicated to invited contributions, presentations and a poster session selected among the participants for the call for contributions on the workshop theme. 

While the submission period for contributions is closing tomorrow, January 31 (h.23:59 AoE), there will still be opportunities to register as participants after the deadline, at the following link: https://forms.gle/Z7J36XSdPa9tkSop7. Please visit https://workshop-oc.github.io/ for all the information. We look forward to meeting you in Bologna!