Abstract: In a method and system for creating an extensible media player, a multimedia player application is instantiated on a client system. A timeline to be played by the instantiated multimedia player application is transmitted to the client system. One or more modules and one or more layouts are dynamically selected and retrieved for the timeline. The modules contain application logic to extend a functionality of the multimedia player application. The layouts contain logic to control an aspect of a presentation of the multimedia player application and the modules. The timeline, the modules, and the layouts are loaded into the multimedia player application. The loaded modules are verified to determine if any module is blocking the timeline from playing. If a module is blocking the timeline from playing, the blocking module is executed and playback of the timeline is stopped until execution is complete. If no module is blocking the timeline, the timeline begins playing back.