On March 10, 2026 , Astro 6.0 shipped as stable, followed by Astro 6.1 in April with image optimization fixes, i18n improvements, and Lightning CSS regression patches. Calling this "a routine major release" badly understates what changed. Astro 6 rebuilt the dev server and build pipeline onto a single shared code path , sat that path on top of Vite's new Environment API , and made non-Node runtimes — Cloudflare Workers, Bun, Deno — reproduce locally in dev exactly as they will run in production. At the same time, the Go-based .astro compiler got a Rust rewrite as an experimental opt-in (compilation phase up to 100× faster on large content sites), the Fonts API and Content Security Policy API got promoted into core, and Live Content Collections — experimental in 5.10 — went stable.…