Servo 0.3.0 covers all changes landed in May across 391 commits. Security fixes include updating SpiderMonkey to 140.10.1 to patch memory safety bugs (CVE-2026-7322, CVE-2026-7323). New web platform features include several font-variant CSS properties, mp4 without fast start in video, multipart form encoding, and new DOM APIs. The embedding API sees breaking changes to cookies, Preferences, and DiagnosticsLogging. servoshell gains --host-file and --userscripts options, plus DevTools Debugger improvements including script blackboxing. Performance improvements span layout optimizations (immutable fragment tree, lazy scrollable overflow, combined traversals), DOM attribute efficiency gains, reduced thread pool usage, and faster build times. Stability fixes address crashes in MediaStream, CSS content, DevTools, and layout. The project also added CI checks to reject AI-generated contributions.
