Ghost models — Pantheon
  
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    # Ghost models

    
a cross-cut of the roster · models announced or expected that never arrived
    
Some models shaped the discourse without ever shipping. They were named in roadmaps, promised in announcements, benchmarked in anticipation — and then didn’t come. The archive keeps their pages because the waiting, the speculation, and the non-arrival are events too. A ghost model’s record is a record of an absence with a shape.

    
## The criterion

    

      
- A model qualifies as a ghost when it was publicly announced or named by its lab and then never released in any form — no API, no weights, no product surface — with the trail gone cold rather than merely pending.
      
- Models still in training or expected on an active timeline (Grok 5, DeepSeek-R2, Kimi K3) are not ghosts yet; they hold ordinary roster entries until they ship or their trail goes cold.
      
- Unreleased internal checkpoints that later surfaced through other models (the Sydney-era GPT-4 checkpoint, gpt2-chatbot) are not ghosts either — they arrived, sideways; their evidence lives on the pages of the models they became or haunted.
    

    
## The ghosts

    

      
- [Claude 3.5 Opus](../claude-3-5-opus/) announced 2024-06 · never shipped — named in Anthropic’s own Claude 3.5 announcement materials as the family’s coming large tier; discussed, awaited, and repeatedly “spotted” through late 2024; no model of that name was ever released. Its page holds the announcement trail and the non-arrival discourse.
      
- [Llama 4 Behemoth](../llama-4-behemoth/) announced 2025-04 · no release as of 2026-07 — announced by Meta at the Llama 4 launch as the family’s ~2T-parameter teacher model, “still training”; subsequent reporting described internal delays. No public release has followed. REPORTED
    
    
Candidates are added here only when the absence itself is documented — an announcement with a name, then silence. If you know of a ghost this page is missing, the [contribution door](https://github.com/llm-pantheon/llm-pantheon.github.io/blob/main/CONTRIBUTING.md) is open; bring dates.

    
## Why keep them

    

      
- Non-arrivals move the field: expectations get priced in, competitors position against phantoms, communities grieve models they never met. The evidence standard is the same as everywhere on this site — dated, verbatim, sourced — it just documents anticipation instead of encounter.
      
- On the roster, ghosts live in their own section rather than among their labs’ shipped models — the roster tracks what arrived; this page holds what didn’t. A ghost’s own page still names its lab.
    

    
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