Z.ai Releases GLM-5.1 Language Model Under MIT License

Chinese AI company Z.ai has released GLM-5.1, a 754-billion-parameter language model that it says outperforms GPT-5.4 and Claude Opus 4.6 on software engineering benchmarks. The model is available under an MIT license, allowing commercial use and modification. Z.ai said GLM-5.1 achieved strong results on SWE-bench Pro, a benchmark that tests models' ability to solve real-world software engineering tasks. The release adds to the growing number of large language models available as open weights. Z.ai joins companies like Meta, Alibaba, and Mistral in releasing major models with permissive licenses. The 754-billion-parameter size places GLM-5.1 among the larger publicly available models, though efficient inference will likely require significant computational resources. Z.ai has not disclosed full training details or the composition of the training data. MIT licensing represents a more permissive approach than some competitors, potentially accelerating adoption among developers and enterprises.