From Italy to Europe: How publiccode.yml is transforming public sector open source software

In today’s rapidly evolving digital landscape, the ability to share, reuse and govern open source software effectively is paramount for modern public services. At the heart of this effort lies publiccode.yml, a metadata specification that is reshaping how public sector open source software solutions are documented, discovered and reused across Europe. What began in Italy has now become a European standard for transparency, interoperability, and high-quality public sector open source.

publiccode.yml was originally developed under the stewardship of Developers Italia, a community dedicated to the development of free software to support Italian digital public services. publiccode.yml provides a standardised, machine readable profile for open source projects. It captures key details such as the name, description, license, development status, and contact information for each solution.  This structured approach empowers civil servants, developers, and policymakers to discover, evaluate, and reuse open source solutions with ease, fostering collaboration through clear documentation. Built on the YAML format, publiccode.yml is simple to use and adaptable, allowing countries to tailor it to their specific needs while maintaining its core functionality.

Since its introduction in 2020, publiccode.yml has become mandatory for all public sector software projects in Italy, setting a benchmark for transparency and interoperability. Italy’s pioneering work laid the foundation for broader European adoption. This evolution reached a new milestone with the launch of the EU Open Source Solutions Catalogue (EU OSS Catalogue) in 2025.

The EU OSS Catalogue uses publiccode.yml as its reference metadata specification, ensuring that every solution meets a baseline of technical clarity and transparency. Adding a valid publiccode.yml file is now a prerequisite for onboarding solutions into the EU OSS Catalogue, making it a cornerstone of Europe’s open source ecosystem. 

To learn more about publiccode.yml, we spoke with Fabio Bonelli, a member of the publiccode.yml Working Group. He shared how governance, collaboration, and stakeholder engagement have shaped the evolution of publiccode.yml. As the primary maintainer of the publiccode.yml repository, Fabio explained that the process is deliberately open and inclusive. Anyone can propose improvements via GitHub, ensuring transparency and community involvement.

The Steering Committee is part of the publiccode.yml Working Group. Currently comprised of six members, the Steering Committee was established to bring structure, continuity and quality assurance to what had previously been an informal, individual-driven process. “Before, contributions depended on proactive individuals,” Fabio noted. While this flexibility had its merits, it lacked resilience against unsuitable inputs. The Steering Committee introduced an institutional framework, balancing structure with openness. Although some degree of bureaucracy was inevitable, automating certain tasks has streamlined operations. Participation remains voluntary and the open, asynchronous nature of discussions reflects the project’s commitment to transparency. Fabio emphasised that the sense of ownership that comes with contributing is a powerful motivator. This collaborative governance model reinforces both the stability and credibility of publiccode.yml, ensuring it remains fit for the evolving needs of Europe’s public administrations.

As the EU OSS Catalogue continues to expand, broader adoption of publiccode.yml across Europe is expected.  Solution owners are encouraged to add a publiccode.yml file to their projects and request onboarding into the Catalogue. This not only enhances solutions visibility and discoverability but also ensures compliance with European interoperability and transparency standards and strengthens Europe’s commitment to digital sovereignty. Details on onboarding requirements are available here. 

Beyond onboarding solutions, EU Member States are invited to contribute to the evolution of publiccode.yml by proposing improvements, participating in community discussions and joining the Steering Committee. This collaborative approach ensures the specification remains robust and adaptable to the needs of a connected Europe.

For those seeking deeper knowledge, online training on both the EU Open Source Solutions Catalogue and publiccode.yml is available through the Interoperable Europe Academy providing practical guidance to help administrations document, publish and reuse open source more effectively.providing practical guidance to help administrations document, publish and reuse open source more effectively.