Phosphene, a menu‑bar app and wallpaper extension, lets macOS Tahoe users play personal videos as desktop and lock‑screen backgrounds. Built on Apple’s private WallpaperExtensionKit, the engine plugs into the system picker so videos sit beside native Aerials in Settings → Wallpaper. The project remains open source after an earlier commercial effort.

The extension loads the private framework via dlopen and mirrors runtime types to communicate with XPC. It delivers gapless, frame‑accurate loops by offsetting PTS across boundaries, and supports multi‑display and per‑Space selections. Power‑aware playback throttles decoding when the device is on battery, in game mode, or idle, keeping the system responsive.

Phosphene also offers a menu‑bar UI for library management, pause toggling, and display switching. The renderer uses AVSampleBufferDisplayLayer instead of AVPlayerLayer to avoid silent failures inside the remote CAContext, ensuring glitch‑free playback. As a free, MIT‑licensed tool, it gives developers and power users a robust alternative to commercial wallpaper solutions.

The project tracks macOS 26 (Tahoe) and requires arm64‑Apple Silicon, Xcode 17+, Swift 6 concurrency, and a development team for code signing. Users launch Phosphene from the menu bar, add MP4/MOV files, and select them in System Settings. The extension persists per‑display choices and adapts to lock‑screen transitions with a cubic ramp, matching Apple’s native Aerials.