Zig Creator Slams Anthropic Over Bun Rewrite Narrative
Original: Zig Creator Calls Spade a Spade, Anthropic Blows Smoke
Why This Matters
Highlights how AI lab narratives and acquisitions are reshaping open-source language ecosystems and engineering culture.
Zig creator Andrew Kelley publicly criticized Anthropic and Bun after the TypeScript runtime was rewritten from Zig to Rust following Anthropic's acquisition. The rewrite, completed by AI agents, was merged within days and later explained two months after the fact, sparking debate about AI's role in software engineering.
Anthropic-acquired Bun, a TypeScript runtime originally written in Zig, underwent a large-scale AI-driven rewrite to Rust. The migration was merged to mainline before any public explanation was provided — the official rationale came two months later. This delay allowed headlines emphasizing AI speed to dominate coverage, such as The Register's 'Anthropic's Bun Rust rewrite merged at speed of AI.' Zig creator Andrew Kelley subsequently published a blunt public response criticizing the decision and the parties involved, which some labeled a 'meltdown' but others praised as necessary candor. Author Ray Myers frames Anthropic's broader messaging — that AI will eliminate coding, software engineering, and eventually most human labor — as strategic narrative-building tied to the company's financial position. Anthropic has raised $132 billion in investment and is approaching a rumored $1 trillion IPO valuation despite lacking profitability. Myers, a former Chief Architect at a coding agent startup and one-time Anthropic customer and competitor, argues that this narrative influences real architectural, product, and staffing decisions driven by fear rather than evidence. Notably, Bun claims near 100% AI-generated contributions, while Zig's project explicitly allows 0% AI contributions — a philosophical divide now at the center of the controversy.