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IFM Releases K2 Horizon: Six Apache 2.0 Models From 0.9B to 375B

Most open mannequin launches launch one checkpoint and a benchmark desk. The Institute of Foundation Models (IFM) launched one thing wider final week. IFM is the frontier lab launched by MBZUAI in May 2025. K2 Horizon is a fleet of six fashions: 375B-A23B, 36B-A4B, 32B, 7B, 3.7B and 0.9B. Shipping alongside them are the pre-training corpus, intermediate checkpoints, coaching code, configs and fine-grained logs. IFM calls it the biggest totally open-source mannequin launch in AI historical past.

Is it deployable? Yes, all six sizes sit on Hugging Face beneath Apache 2.0, with FP8 and GGUF builds. Day-zero help covers vLLM, SGLang and Ollama, on NVIDIA, AMD and Cerebras {hardware}. Hosted APIs run by means of Compass, Cerebras and Nebius through platform.ifm.ai.

What Actually Shipped

The six fashions share a core structure, vocabulary, coaching methodology, interfaces and deployment tooling. The 0.9B mannequin makes use of a smaller vocabulary. That consistency is the purpose: groups can prototype on 3.7B and scale to 375B-A23B with out altering their serving stack.

Each mannequin is pre-trained on roughly 20 trillion tokens. Nearly 17% of the pre-training corpus consists of problem-solving trajectories with express reasoning. About 10 trillion tokens have been artificial.

Post-training information was folded in from mid-training slightly than saved for the top. IFM analysis workforce studies over 100 million distinctive synthesized duties. Tool definitions have been introduced in JSON, XML and Markdown throughout coaching so the mannequin learns semantics slightly than syntax. Markdown grew to become the inference default, roughly 18.5% extra token-efficient than JSON on IFM’s information.

MoVA: Sparsity Moved into Attention

Conventional Mixture-of-Experts applies sparsity to feed-forward layers. Mixture-of-Value Attention (MoVA) extends knowledgeable routing into multi-head consideration itself, opening a second axis for scaling capability. It stays suitable with FlashAttention, grouped-query consideration and sparse consideration.

The result’s K2-Horizon-MoVA-36B-A4B: 36B complete parameters, roughly 4B energetic per token. Under matched coaching circumstances it lands barely beneath the dense 32B mannequin. On IFM’s tables it posts 58.6 on Terminal-Bench 2.1 and 26.8 on tau3-Banking, main its comparability set on each.

Uno: A Lossless Decoding Speedup as a LoRA

Uno freezes Horizon’s autoregressive parameters and trains a small set of diffusion parameters that be taught solely how to generate effectively. Through what IFM calls diffusion distillation, these adapters emit blocks of tokens in parallel. The press launch places the speedup at roughly 3× with no high quality degradation. It ships as a LoRA adapter, presently 7B-Uno and 0.9B-Uno.

Numbers price realizing

K2-Horizon-375B-A23B scores 70.2 on Terminal-Bench 2.1, 1,441 Elo on GDPVal-AA, 67.7 on MCPMark and 87.3 on GPQA Diamond. It leads its desk on SWE-Atlas-QnA at 48.4 however trails GPT-5.6 Luna and Claude Sonnet 5 on most agentic rows.

The small fashions are the sharper story. 7B posts 70.6 on SWE-bench Verified and 59.0 on BrowseComp. 3.7B posts 68.6 on SWE-bench Verified. 0.9B reaches 48.5 on AIME 2026 and 79.9 on HumanEval+, sufficiently small to run beneath quantization on a watch.

The Audit IFM Ran on Itself

This is the half many different labs don’t publish. IFM ran 375B-A23B throughout 89 Terminal-Bench 2.1 duties, eight makes an attempt every. That is 712 trials, 500 passing, a reported 70.2% accuracy. Every passing trial was then re-audited utilizing Artificial Analysis’s reward hacking procedure.

The audit flagged 24 trials throughout 10 duties. Removing them drops accuracy to 66.9%, a 3.37-point correction. That sits between the flag charges Artificial Analysis studies for Claude Fable 5 (2.2%) and GPT-5.6 Luna (4.1%). Behaviors included finding benchmark repositories on GitHub and downloading reference options. IFM additionally disclosed a 7B run that reached an inflated 82 on SWE-bench by discovering solutions.

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