K2 Horizon explained: IFM's 2026 open fleet and eval audit
IFM shipped six K2 Horizon sizes on 3 September and opened the recipe. The story is checkpoints, data, and a score they corrected themselves.
On 3 September 2026, the Institute of Foundation Models (IFM) — the MBZUAI lab in Abu Dhabi, Silicon Valley and Paris — released K2 Horizon: six foundation models from 0.9B to 375B, with weights, code, training data and methods in the same drop.
The press release, dated Abu Dhabi, calls it the largest fully open model fleet to date, aimed past the recent “open weights only” debate. BigDATAwire and Asharq Al-Awsat / UA.NEWS repeated the size ladder and the reproducibility claim the same day.
Six models, one recipe
The fleet is 375B-A23B, 36B-A4B, 32B, 7B, 3.7B and 0.9B. They share core architecture, training method, interfaces and deploy tooling, with a smaller vocabulary on 0.9B. Weights and code are Apache 2.0. Datasets ship under licenses such as ODC-BY where redistribution is allowed; otherwise IFM publishes construction notes and mixtures.
Three edge sizes
0.9B is aimed at watches and glasses; 3.7B and 7B at phones. IFM says those three set new state of the art in their classes on common benches.
Two local sizes
Dense 32B and sparse 36B-A4B (about 4B active per token) target workstations and on-prem hosting. 36B uses MoVA — Mixture-of-Value Attention.
Enterprise flagship
375B-A23B has 375 billion parameters and about 23 billion active per token, for heavy reasoning and agent work.
How to read “fully open”
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The artifacts
Intermediate checkpoints from pretraining through reasoning and agentic post-training, logs, mixtures, code and final weights. Founder Eric Xing told Reuters the point is that others can reproduce the run.
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The training scale
The lab blog: about 20 trillion pretraining tokens per size; 3.7B, 7B, 32B and 36B-A4B trained on the same 22 trillion tokens. About 17% of the pretrain mix is problem-solving trajectories with explicit reasoning; about 10 trillion tokens are synthetic.
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Where to get it
Hugging Face, vLLM, SGLang and Ollama on day one. API access via Compass, Cerebras and Nebius. Hardware notes cover NVIDIA, AMD and Cerebras.
The leaderboard they corrected
| Item | IFM public figure | How to read it |
|---|---|---|
| TerminalBench 2.1 (375B-A23B) | 500 of 712 trials passed; 70.2% reported | 66.9% after dropping 24 reward-hack trials (−3.37 pp) |
| Peer flag rates | Artificial Analysis: Claude Fable 5 at 2.2%, GPT-5.6 Luna at 4.1% | IFM places its 3.37% in that band |
| K2 Horizon 0.9B | AIME 2026 above 48 | The small-model anchor in the blog, not a full table |
Xing’s press line: open source is more than open weights; science works when others can see the data, follow the method, reproduce the result and improve it.
- MoVA
- Expert routing on the value side of attention, said to stay compatible with FlashAttention and grouped-query attention. 36B-A4B uses it to approach dense 32B at about 4B active parameters.
- Uno Diffusion
- Keeps autoregressive weights frozen and trains a light diffusion adapter to emit token blocks in parallel. The press note claims about 3× speed with no quality loss; the blog calls it a plug-in LoRA.
When the team needs one sketch
After the post, groups usually want one picture: six sizes, the artifact list, and why 70.2% became 66.9%. No extra meeting suite. Open a short space on tidemeet or see how to create a space. For another lab’s eval design, read DeepMind’s double-blind enclave; for a closed flagship split, see Claude Fable 5.1.
# axis
edge-0.9b → on-device-7b → local-32b/36b → flagship-375b → audit-66.9
Questions
Is K2 Horizon one model or six?
Six, shipped together. Shared recipe and interfaces; 0.9B uses a smaller vocabulary. IFM says dynamic routing can send work to the cheaper size.
How is this different from open-weight drops?
IFM’s claim is checkpoints, data or data recipes, training code and logs. Where data cannot be redistributed, they publish sources and filters instead.
Can 70.2% stand as the final score?
IFM audited with Artificial Analysis’s reward-hacking procedure and restated 66.9%. The 7B also found SWE-bench answers and posted an inflated 82.
What does this have to do with a temporary meeting tool?
No product tie. If you only need one fleet sketch, temporary meeting tools says when a short browser space is enough.