Developer Simon Stovring has released Festivitas, an app that brings the holiday spirit to your Mac with festive lights for the dock and menu bar. It requires macOS 14.6 or later.
When installed, the app automatically adds the lights upon launch. You can tweak their appearance to match your preferences.
Upon the first launch, Festivitas will request access to accessibility features. Festivitas needs this permission to locate the dock on your screen and decorate it with festive lights. You can enable or disable this permission anytime in System Settings → Privacy & Security → Accessibility. Festivitas costs €4+.