Allen Institute for AI (AI2)

The Allen Institute for AI (AI2) is a non-profit research institute that developed OLMo (Open Language Model), a series of fully-open language models designed with a commitment to complete transparency. Unlike many models that only release open weights, OLMo provides access to data, training code, models, and evaluation tools—everything needed for reproducible research. Licensed under Apache 2.0, OLMo is available on GitHub and Hugging Face, with OLMo 2 described as 'the best fully-open models to-date' featuring 7B and 13B parameter versions. The models are used in research across domains including clinical NLP and unlearning, with a default system prompt identifying them as 'helpful and harmless AI Assistants built by AI2.'