Research-only reasoning models
1 in the catalogue today, and the list grows as the market does. Every one with what it costs, who sells it and where it stands.
Models that plan before they answer, spending extra tokens on working the problem through. They win on mathematics, hard code and anything with several steps, and they are measured on boards like GPQA, AIME and ARC-AGI. The catch is what the thinking costs: reasoning is billed as output tokens, so the same model can cost several times more per answer at a high effort than a low one, and for a question that needed one turn you have paid for a monologue.
Weights published for research and explicitly not for selling. They are here because they exist, are often excellent, and are worth knowing about — and because the cheapest way to learn this is not after you have shipped. If a model on this list is what you want, the maker will usually license it commercially on request; that is a conversation, not a download.