The Institute of Foundation Models (IFM) released K2 Horizon, a fleet of six AI foundation models ranging from 0.9 billion to 375 billion parameters, on September 3, 2026. ^[1] IFM announced the release of K2 Horizon, a fleet of six open-source AI models (375B-A23B, 36B-A4B, 32B, 7B, 3.7B, and 0.9B) designed to span deployment from edge devices to enterprise. ^[2] IFM claimed that the 0.9B, 3.7B, and 7B K2 Horizon models set new state-of-the-art performance in their respective size classes across reasoning, mathematics, coding, and agentic tasks. ^[3] IFM stated that the K2 Horizon models are fully open, including model weights, code, training data, and methodologies, to allow researchers and developers to inspect, reproduce, and adapt them. ^[4] K2 Horizon models are available immediately through Hugging Face, vLLM, and SGLang, with the API available through partners including Compass, Cerebras, AWS, and Nebius, all under the Apache 2.0 license, according to IFM. ^[5] IFM claims the 0.9B, 3.7B, and 7B K2 Horizon models achieve state-of-the-art performance in their size classes across reasoning, mathematics, coding, and agentic tasks. ^[6] IFM states that K2 Horizon is its most comprehensive open release to date, opening the full training lifecycle from pretraining through agentic post-training, including intermediate checkpoints, training data or recipes, code, configurations, and logs. ^[7] IFM says the K2 Horizon 375B-A23B model has 375 billion total parameters with about 23 billion active per token, ranking among top models below 400 billion parameters. ^[8]