Title: 42 months in the making: OpenWebSearch.EU project end results look promising!
While the project officially ended on 28 February 2026 with very positive results, the journey continues under the European Open Web Search initiative. But first things first…
How it started and where we are at
In September 2022 a consortium of 14 European organizations*, spread across 7 countries, have joined into the Horizon Europe funded project OpenWebSearch.EU, with the goal to conceptualize, develop, test and evaluate a first ever publicly federated European Open Web Index.
A Web index per se is a necessary fundament for any search engine (including LLM based agentic search applications) to draw information from. Without a well-structured Web index that processes and stores up-to-date crawls, thereby mapping out the World Wide Web, search practically cannot operate. An “open” web index refers to the standards of open source technologies, meaning that the index is accessible publicly and transparent in its nature.
Why that matters?
Europe, with its longstanding and multi-cultural history, has not yet managed to create a sovereign European web data infrastructure that is inclusive of the socio-cultural and linguistic diversity that makes up the European identity. Instead, accessing information online is still largely dependent on overseas Big Tech services that do not fully represent the digital needs and views of European societies. In addition, these services, as by their commercial nature, are not free of biases, e.i. in political, cultural and commercial regards.
But why has Europe not yet created a web index of its own then?
There have been some commercial companies that have made attempts at creating indices in the past and present, and some of them have had a certain level of success. But maintaining an index is a costly endeavor. The enormous need for computing, storage and maintenance requires solid funding.
Another component is the lack of a true pan-European ambition. Solutions on national levels might work on a certain level, but they so far do not suffice to cater to pan-European needs. Europe, by its history, is not one homogenous continent, but a collective of individual countries, languages and cultures that should benefit from a European Web index equally.
Birthing a truly European search infrastructure, that meets people’s expectations, will ideally be curated collaboratively and across country borders. This is where the OpenWebSearch.EU project is unique in its federated design. Additionally, ethical aspects are included by design. This means to foster inclusion, diversity, transparency, while honoring copyrights and guaranteeing privacy protection.
So, what project objectives and milestones have been reached?
The biggest milestone by far and a key project result has been the successful launch of the Open Web Index (OWI) prototype in May 2025.
The index has been developed by teams from five technical workpackages, including team members from the University of Passau, CERN, German Aerospace Center, A1 Slovenia, Radboud University, Graz University of Technology and Webis Group. The tech-related infrastructure and governance tasks were managed by teams from LRZ, German Aerospace Center, CERN, IT4I and CSC – IT Center for Science.
The OWI can be accessed publicly via the OWI dashboard, which allows users to download index shards under a dedicated research license, conduct an ethical self-assessment and get regular index statistics updates: https://openwebindex.eu
Users can download index data via the Lexis Platform (provided by IT4I) or the OWI command line tool OWILIX, both of which are offered via the dashboard.
Curious, how index data can be used?
Various Third-Party Partner projects give insights into practical applications and future ideas. Once the OWI was ready for early adoption trials, nine technical projects, two infrastructure projects, one economic and three legal projects were selected and financially supported via three distinct OpenWebSearch.EU open calls.
The results of these projects can be found here: https://openwebsearch.eu/third-party-projects/
Some highlights include the successful implementation of an argument search engine to assess trustworthy health data with fairness-conscious ranking, as well as an innovative LLM based crawling method to outperform traditional PageRank heuristics.
Yet another interesting project is the vertical search engine Nooon, that gives access to disability related data and makes results sharable in trustworthy ways.
How the OWI can boost European economy
To back up the immense Marco-economic potential of an Open Web Index for Europe, the 2024 „Market potential assessment of OpenWebSearch.eu“ study was conducted by third-party partner MRC.
The project team analyzed the economic and societal impact of an open Web index, using both top-down and bottom-up methods to ensure a comprehensive analysis of different scenarios, including qualitative feedback from potential future users.
Key findings indicate that the OWI could achieve a return on investment within four years of operation, with a projected net benefit of around €4.5 billion over a decade. These benefits are believed to derive from economic gains and societal improvements such as strengthening European digital sovereignty and global technological competitiveness across a wide range of industries and use cases. Find the full study for download here: https://openwebsearch.eu/the-project/research-results/market-potential-assessment-of-an-european-open-web-index/
Some lessons learned
Despite many successful results, some challenges have been present as well.
The current scope of the OWI is not yet able to compete with commercial search indexes, such as Google or Microsoft Bing. And while directly competing with these commercial players has never been the idea, scaling up accordingly is a necessity to make the Open Web Index a tool for digital sovereignty.
The OpenWebSearch.EU team is still working to launch the first search API and operational search frontend for the index and legal questions regarding commercial licenses and EU regulatory work still need to be solved for commercial use.
However, the project illustrates and gives evidence that an open Web index on a federated public-private infrastructure is more than doable. This approach adds to sovereignty in web search, AI and web analytics and can be scaled up, if financial backing is provided and if more infrastructure partners are willing to join.
What’s next?
As mentioned in the beginning, the end of the project marks the start the next ventures in the exciting journey of the Open Web Search initiative.
A majority of the project partners are currently working on continuation set-ups. The initiative is largely coordinated by the Open Search Foundation with the University of Passau in the technical driver’s seat. The goal is to keep growing, gain reliable financial and legal support from political stakeholders in Brussels and European Member States and to further grow the community of developers and users.
An important part of the OpenWebSearch.EU project were the community building activities as well as communication and dissemination of research results. The community will be kept up to date via the Mattermost community platform and via OpenWebSearch.eu and OpenSearchFOundation.org Newsletters.
Putting people first was and is the ultimate goal.
While the idea of „European Open Web Search and trustworthy AI as a public good“ is still the mission, it takes active support and engagement from the public to guarantee success.
Is Europe ready to become sovereign in the Web? Now, that that a proof of concept is here, will the Europe take the next step?
It is up to European citizens, politicians, and decision makers to make the call now! A big thanks to everyone who has supported the OpenWebSearch.EU project in the past 3,5 years! Many thanks to Horizon Europe and Next Generation Internet! And a special thanks to the entire OpenWebSearch.EU teams for walking this exciting walk together!
*University of Passau (Germany), Leibniz Supercomputing Centre (Germany), Radboud University (The Netherlands), Leipzig University (Germany), Graz University of Technology (Austria) German Aerospace Center (Germany), IT4I (Czech Republic), CERN (Switzerland), Open Search Foundation (Germany), A1 Slovenija (Slovenia), CSC – IT Center for Science (Finland), nl Net Foundation (The Netherlands), Suma-ev (Germany), Webis Group (Germany)
