Betsy Masiello and Derek Slater are the founding partners of Proteus Strategies, a boutique tech policy strategy and advocacy firm. Rens Dimmendaal & Johann Siemens / Better Images of AI / Decision Tree reversed / CC-BY 4.0 As we approach the year’s midpoint, it would be the understatement of 2023 to say that there is a lot of buzz around AI, particularly large language models and other powerful, ‘foundation’ models. While somewhat cacophonous, this dialogue is on the whole a good thing – AI may impact every aspect of our lives in the not too distant future, and now is the time to design policy interventions that will influence that future for the better. One area that is increasingly salient in the policy discourse is the role of open source software, and openness more generally, in the development of the AI market. There is a gradient from closed to open approaches to the development and release of AI products, the precise bounds of what constitutes ‘open source’ in this context is still contested, and there are a range of policy takes on the open source end of that gradient. Points of debate include who should have liability for open source vulnerabilities, and how open source may help address or exacerbate safety concerns. We focus here on the role of openness in preserving a competitive marketplace where new entrants, small companies, nonprofits and others will have access to the tools of innovation. Many of the perspectives on this issue land at one…Will Open Source AI Shift Power from ‘Big Tech’? It Depends.