Foundation models and the labs that build them

Model developers in this catalog make their models available in different ways. Some offer them as hosted services: Anthropic's documentation lists each Claude model by its ID on the Claude API and on cloud platforms run by Amazon, Google, and Microsoft. Some publish the weights: Ai2 says its Olmo 3 models were pre-trained on the Dolma 3 dataset and post-trained on the Dolci datasets, and that it is releasing the code, checkpoints, and training details. Others do both. OpenAI serves models through its API and also publishes gpt-oss, which its model card calls OpenAI's open-weight models, under the Apache 2.0 license.1534

A model name often covers many releases. The Olmo 3 model card lists 7B and 32B models in Instruct and Think variants, and publishes a separate checkpoint for each training stage (supervised fine-tuning, preference tuning, and a final reinforcement-learning stage). In this catalog, a family record summarizes a named line of models, while licenses, availability, and openness tiers attach only to individual releases, because they can differ between releases in the same family.510

Downloadable weights come with different terms. Gemma 4 and gpt-oss use Apache 2.0. The Llama 4 Community License incorporates an acceptable use policy and requires anyone who distributes the models, or a product that contains them, to display "Built with Llama"; a model trained or improved with them and then distributed must have a name beginning with "Llama". The Llama 4 Scout repository on Hugging Face asks you to sign in and review these conditions before access. The xAI Community License for Grok 2 allows commercial use only within xAI's acceptable use policy and bars using the materials or their outputs to train other general-purpose models.64789

A permissive license does not settle every question. Ai2's Olmo 3.1 32B Think card gives an Apache 2.0 license and also says the model is intended for research and educational use in line with Ai2's Responsible Use Guidelines. The catalog keeps availability separate from permission: being publicly downloadable does not by itself make a release unrestricted, open source, commercially usable, or redistributable.510

Hosted models change on the provider's schedule. Anthropic says every Claude model ID is a pinned snapshot, that a deprecated model is given a retirement date, and that requests to a retired model fail. It gives at least 60 days' notice before retiring publicly released models on the platforms it operates, while Amazon Bedrock and Google Cloud set their own schedules. Check the lifecycle page for any hosted model you build on.12