The stealth model has an owner: Ox Alpha came from Z.ai's GLM series
The model nobody could place a few days ago turns out to be Chinese lab Z.ai's, confirming early guesses. The weights ship Wednesday.
Models
Z.AI
How Chinese labs keep pace — and why the answer is not distillation
GLM-5.3 reached the frontier with a third of Kimi K3's parameters. The analysis argues the reason is not distillation but post-training depth and a decade of accumulation.
Companies
Z.ai Releases GLM-5.3 Using the Same Base Model
Z.ai has introduced GLM-5.3, using the same 743-billion-parameter base model as GLM-5.2; all improvements came from post-training scaling.
Models