The EUPL is the only open-source license that explicitly uses European legal terminology and references EU jurisdiction. Despite this, it is barely used in the frontend space. While MIT and GPL are based on US legal concepts, the EUPL speaks the language of European law – literally, as it is legally valid in all 23 EU official languages.

Origin and Purpose

The European Union Public Licence was developed in 2007 by the EU Commission to provide an open-source license compatible with the European legal framework. The current version 1.2 dates from 2017.

While US licenses use terms like “Copyright holder” and “Licensor,” the EUPL uses European legal terminology. The jurisdiction is the competent court of the EU Member State of the licensor – not a US court, as would be the case in disputes over MIT or GPL-licensed code.

An often-overlooked aspect: each of the 23 language versions is equally legally valid. In a dispute, the language version of the Member State where the licensor is established applies. A German company can therefore rely on the German license text – an advantage no other open-source license offers.

Copyleft with Compatibility

The EUPL is a copyleft license – derivative works must be published under the same or a compatible license. Unlike the GPL, the EUPL offers an explicit compatibility list (appendix to the license). Derivative works may also be distributed under: GPL v2/v3, LGPL v2.1/v3, AGPL v3, MPL v2, CECILL v2.0/v2.1, Eclipse Public License, and Apache 2.0 (only for EUPL v1.2).

This makes the EUPL significantly more flexible than the GPL. In practice: a EUPL-licensed design system can be used in projects using GPL, Apache, or MPL – broad coverage of common open-source ecosystems.

What the EUPL Means for Design Systems

For a design system under EUPL: any organization can use the components, including commercially. Modifications must be published under EUPL or a compatible license – but the copyleft refers to the library itself, not the products using it. Using the library as a dependency does not create a derivative work – copyleft only applies when modifying and redistributing the library source code.

Relevance for Public Sector

For public sector organizations, the EUPL is particularly relevant. The EU Commission recommends it for all publicly funded software. In several EU countries, it is already the standard license for publicly funded software projects.

EUPL Compared

Property
MIT
GPL v3
EUPL v1.2
Copyleft
No
Strong
Weak
Compatibility list
–
No
Yes (10+ licenses)
Patent clause
No
Yes
No
Language versions
English
English
23 EU languages
Jurisdiction
Unclear (US-based)
Unclear (US-based)
EU Member State
Public sector
No preference
Rare
EU recommendation

Key Takeaways

  • The EUPL is legally valid in 23 EU official languages – each language version is equivalent.
  • As a copyleft license, it requires disclosure of derivative works but offers broad compatibility with GPL, Apache, MPL, and more.
  • The jurisdiction is the competent court of the EU Member State – not US jurisdiction.
  • The EU Commission recommends the EUPL as the standard for publicly funded software.
  • For design systems: using it as a dependency does not create a derivative work – copyleft only applies to modifications of the library itself.
  • The EUPL is the most consistent license choice for EU organizations serious about digital sovereignty.