Bun 1.4, the first stable release rewritten entirely in Rust after migration from Zig, ships with 2,900+ bug fixes and significant performance improvements: 5× lower idle CPU usage, up to 35% memory reduction, 2× faster startup on Linux and 2.5× on Windows. The release adds built-in APIs (Image, WebView, markdown, cron, Terminal) to reduce external dependencies, passes 1,517 additional Node.js compatibility tests, and introduces HTTP/3 support and new platforms (FreeBSD, Windows ARM64, Android). Already battle-tested by Claude Code and Prisma Compute, this represents a major milestone for developers seeking a faster, more efficient Node.js-compatible runtime.