Arcee

Arcee AI is a San Francisco startup founded in 2023 by Mark McQuade (CEO), Brian Benedict (CRO), and Jacob Solawetz (CTO) — McQuade and Benedict are former early Hugging Face employees. $29.5M raised from Emergence Capital, Prosperity7, M12 (Microsoft), Samsung Next. Targeting $1B+ in a 2026 raise.

Arcee represents a rare independent US open-source frontier effort. The Trinity family (Jan 2026) was pretrained from scratch: Trinity Large (398B/13B active MoE, 256 experts, 17T tokens, 2,048 B300 GPUs in 33 days, ~$20M) achieves MMLU 87.2 and reached #1 most-used open model in the US on OpenRouter. Architecture uses DeepSeekMoE-style fine-grained routing, interleaved local/global attention, and the Muon optimizer with zero loss spikes. Trinity-Large-Thinking adds reasoning with tau2-Airline 88.0% and AIME25 96.3%. All Apache 2.0.

Also produced MergeKit, the most widely-used open-source model merging toolkit, and DistillKit for knowledge distillation.