Arcee’s new, open source Trinity-Large-Thinking is the rare, powerful U.S.-made AI model that enterprises can download and customize
Carl Franzen April 3, 2026 Credit: VentureBeat made with Google Gemini 3.1 Pro ImageThe baton of open source AI models has been passed on between several companies over the years since ChatGPT debuted in late 2022, from Meta with its Llama family to Chinese labs like Qwen and z.ai. But lately, Chinese companies have started pivoting back towards proprietary models even as some U.S. labs like Cursor and Nvidia release their own variants of the Chinese models, leaving a question mark about who will originate this branch of technology going forward. One answer: Arcee, a San Francisco based lab, which this week released AI Trinity-Large-Thinking—a 399-billion parameter text-only reasoning model released under the uncompromisingly open Apache 2.0 license, allowing for full customizability…
