Fable 5 wrote a Windows kernel in 38 minutes · Tolmo

▤ Summary

The article describes how Fable 5 generated a booting Rust-based NT-compatible kernel in 38 minutes and then contributed to a broader project that later loaded Windows drivers and user-mode binaries. It emphasizes that the kernel acts as a trusted computing base, making correctness, verification, and safety the real challenge rather than code generation itself. The piece also explains how model choice shaped the workflow, with Fable handling rapid greenfield scaffolding and Opus handling the longer debugging and security-heavy work. It argues that AI can accelerate infrastructure rewrites, but verification remains the bottleneck before anyone can trust AI-authored core systems.

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