Llama is Meta's open-weight model family. Llama 4 was its last major generation; Meta's active assistant-model development has shifted to Muse.
Meta introduced LLaMA in February 2023, helping catalyze the modern open-weight model ecosystem. Llama 2 added commercial use and chat tuning, while the Llama 3 series improved scale, multilingual support, and instruction following. Llama 4, released in April 2025, introduced native multimodality and a mixture-of-experts architecture. Meta subsequently shifted its actively promoted assistant-model line to the proprietary Muse family, but Llama models remain widely used and deployed.
Further reading
Nemotron is NVIDIA's open model family for efficient reasoning, coding, long-context analysis, and agent orchestration. Nemotron 3 Ultra is the current flagship.
NVIDIA introduced the Nemotron 3 family in December 2025 with Nano, Super, and Ultra tiers. Nemotron 3 Ultra, released in June 2026, is a 550B-parameter hybrid Mamba-Transformer mixture-of-experts model with 55B active parameters and a one-million-token context window. It is optimized for long-running agent workflows, tool use, code, multilingual reasoning, and high-stakes retrieval. NVIDIA publishes the weights, training data, recipes, and fine-tuning workflows under the OpenMDW-1.1 license.
Further reading
Llama