When OpenAI unveiled its first open-weight models in years this August, it wasn’t just tech companies that were paying attention. Lilt previously developed its own AI models or used open source options such as Meta’s Llama and Google’s Gemma. The ChatGPT maker’s new open-weight models, gpt-oss-120b and gpt-oss-20b, changed that. In a recent McKinsey survey of roughly 700 business leaders, more than 50 percent said their organizations use open source AI technologies. OpenAI did not respond to requests for comment about how its open source models may be used by the defense industry.