Anthrophic's Bun team trials port from Zig to Rust

Bun creator Jarred Sumner has committed a Zig-to-Rust porting guide to GitHub, sparking speculation about a potential migration of the JavaScript runtime away from Zig. The move is partly driven by friction with Zig's strict no-AI contribution policy, which conflicts with Anthropic's (Bun's owner since late 2025) AI-first development philosophy. Sumner has not committed to a full rewrite, describing it as exploratory. Additional motivations include Zig's instability as a pre-1.0 language and breaking changes. The community has reacted with cautious interest, noting Bun's history of bugs and memory leaks. Sumner also predicted that open source projects will increasingly ban human contributions in favor of LLMs.