First Firefox and Zen release. Includes all 298 appearance and behavior controls, the native Firefox sidebar, focus sessions and usage limits, content filters, presets, settings protection with delayed recovery, player controls, optional Google Fonts, and Channel Play all. English and Russian interfaces are included. Requires desktop Firefox 153 or later.

Settings and protection records are stored locally in extension-origin IndexedDB. No account, telemetry or developer backend.

Known limits: YouTube layouts vary; ad skipping is experimental. Fullscreen may require a Play gesture, and video sizing was inconsistent in one Zen profile even with YFE player features disabled.