Open sourcing AI: intellectual property at the service of platform leadership Muñoz Ferrandis Carlos Duque Lizarralde Marta Artificial Intelligence (AI) is one of the most strategic technologies of our century. Consequently, tech companies are adopting intellectual property strategies to protect their investment in the field, which encompasses copyright, patents, and trade secrets. While the number of AI-related patent applications is increasing, the number of open-source AI projects sponsored by major AI patent holders is also on the rise. This article explores the commercial and policy strategic reasons behind the growing adoption of open-source licensing in the AI space. More precisely, it assesses how IP rights are articulated around “openness” as a competitive factor in ecosystem competition, and how some players are using open-source licensing successfully to attract a critical mass of users and build an ecosystem around their AI platforms. Moreover, this article integrates the debate on the protectability of AI features by IP rights to assess the potential implications for open-source. Finally, it analyses the most used open-source licenses in AI projects and highlights existing and future challenges from an IP and contractual law perspective. AI copyright licenses open-source patents platforms 340 periodical academic journal JIPITEC 13 3 2022 224 246 2190-3387 urn:nbn:de:0009-29-55579 http://nbn-resolving.de/urn:nbn:de:0009-29-55579 muñoz ferrandis2022