Mux has been working on an open-source project called Media Chrome, which separates UI components from the playback engine. This separation allows designers and front-end developers to focus on player UX without worrying about the underlying playback technology. The project uses HTML and CSS for styling and offers a range of customizable slots for different layouts and icons. Currently, Media Chrome is aimed at developers and designers building playback experiences on the web, with plans to expand its offerings in the future.