Meta and Reflection Ship Open Weights; Microsoft Exits Nscale's Grid-Stalled UK Site — October 19, 2026

Meta's 816B Muse Spark Open and Reflection's 501B Beam both landed as open weights on Hugging Face last week, with very different memory bills. Microsoft walked away from Nscale's Loughton data center as its grid connection slips to the 2030s, and Anthropic is pitching a federal safety bill that would let only Commerce halt a model release.

In this episode

1. Welcome Muse Spark Open: open-weight frontier multimodal mixture-of-experts model from Meta — Pedro Cuenca, ben burtenshaw, Guarin Flück, Quentin Gallouédec, Alvaro Bartolome“Muse Spark Open is an open-weight model from Meta. The mixture of experts model brings text, images, audio, and video into a model with approximately 816 billion parameters, around 42 billion active per token, and a context window of up to one million tokens. It generates text,…”
2. Welcome Beam: a 501B open model you can own, customize, and scale — ben burtenshaw, Pedro Cuenca“Only 8 experts run per token, so the model computes each token with about 23B parameters. All 256 experts stay in memory, so deployment needs the memory of a 501B model but runs at the speed of a 23B one. The BF16 checkpoint is about 1 TB in safetensors format.”
3. Microsoft Reportedly Exits Nscale's Loughton AI Data Center Deal in the UK as Grid Connection Lags — Xenospectrum“Microsoft has withdrawn from its agreement to use an AI data center being developed with Nscale in Loughton, Essex, the UK's Telegraph reported on October 18. The 2025 announcement said the site would deploy 23,040 NVIDIA GPUs, with delivery planned for January to March 2027.…”
4. Anthropic’s proposed AI safety bill only kicks in if 50 deaths or $1 billion in damages are on the line — Jowi Morales“Anthropic is quietly lobbying for an AI safety bill that will allow the government to block an AI model's release only if it poses a risk of causing $1 billion in damages or killing or injuring more than 50 people.”

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