EU lawmakers urge strict definition of open source AI in EU’s AI Act

A coalition of 30 progressive Members of the European Parliament (MEPs) has taken a firm stance on the implementation of the EU’s Artificial Intelligence Act, specifically regarding how ‘open source’ AI should be defined. In a letter sent on 10 April 2025, lawmakers, led by Birgit Sippel from the Socialists and Democrats (S&D) group and Markéta Gregorová from the Greens, warned the European Commission against diluting the definition of open source AI to include models with restrictive licensing terms.

The MEPs specifically singled out Meta, Facebook’s parent company, for what they describe as misleading claims about its AI models being ‘open source.’ They point out that despite Meta’s public championing of openness, the company imposes significant restrictions on its Llama models, including prohibiting their use for training other AI systems and requiring special license negotiations for any commercially successful applications developed with these models.

‘Meta prohibits the use of its Llama models for the purpose of training other AI systems, and forces anyone who develops a highly successful AI system based on Llama to negotiate a special licence with them,’ the letter states. The legislators bluntly summarize Meta’s approach: ‘Their AI is only free and open until a business wants to compete with them.’

In their call for clarity, the MEPs defer to the Open Source Initiative, which has explicitly excluded Meta’s models from its definition of open-source AI. They argue that a weak definition would ‘risk undermining the implementation of the AI Act, putting citizens’ rights at risk, and harming European Competitiveness.’