OpenAI’s new algorithms, gpt-oss-120b and gpt-oss-20b, are available under an open-source license. Anthropic, for its part, released an upgraded version of its proprietary Claude Opus 4 large language model. The update improves upon the LLM’s coding capabilities, which the company claims already outperformed the competition.

The two new models from OpenAI are available under the Apache 2.0 license, a popular choice for open-weight models. With Apache 2.0, models can be used for commercial purposes, redistributed, and included as part of other licensed software. Open-weight model releases from Alibaba’s Qwen as well as Mistral also operate under Apache 2.0.

Despite the company's name, OpenAI hasn't dropped an open version of its AI models since GPT-2 in 2019. That changed on Tuesday, as CEO Sam Altman shared two new open-weights, reasoning AI models, named gpt-oss-120b (120 billion parameters) and gpt-oss-20b (20 billion parameters).