Deepseek R1 is the closest thing we have to fully open-source currently. Open enough that Huggingface is recreating R1 completely out in the open. https://github.com/huggingface/open-r1
What they’re recreating is the evidence that some of the techniques work. But they’re starting with R1 as the input into those steps, not starting from scratch. I don’t think their work includes creating a base model.
