OLMo is an open-source natural language generation model developed by Allen AI Research Institute, based on the Transformer architecture. It is capable of generating high-quality English text and has the ability to produce texts up to 4,096 tokens in length. OLMo-7B is one of the largest open-source English language models currently available, boasting 6.9 billion parameters. It outperforms similar models on multiple English NLP tasks. It can be applied to various natural language processing tasks, including text generation and task-oriented fine-tuning.