# clm_B30193E8CE6E

subject: Preferred Networks (/record/preferred-networks.md)  
predicate: released  
value: Optuna  
valid_from: 2026-09-07  
valid_to: null  
published: 2026-09-07  
recorded: 2026-11-08  
confidence: 0.70  
status: valid  
assertable: true  
superseded_by: null  
last_updated: 2026-11-08  
cite: AsOf. "Preferred Networks released: Optuna", as of 2026-09-07. Claim clm_B30193E8CE6E, https://asof.is/claim/clm_B30193E8CE6E, accessed 2026-11-09. Source: https://www.preferred.jp/en/news/pr20260907.  
checked: 2026-11-08 · its source page states the value and the date  

> TOKYO – September 7, 2026 – Preferred Networks, Inc. (PFN) today released Rustuna™, a Rust-based implementation of the open-source hyperparameter optimization framework Optuna ™, alongside Optuna v5.0, a major update to the framework PFN has led developing since 2018.

What https://www.preferred.jp/en/news/pr20260907 says, word for word.

## Sources

- https://www.preferred.jp/en/news/pr20260907 (primary, Preferred Networks, published 2026-09-07)

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