FlashSound API extensions are JavaScript libraries that extend the core capability of the flashsound.js. Anyone familiar with object oriented JavaScript can create an extension to add new capabilities to the FlashSound API.

ActionScript Extension
The FlashSound Actionscript extension extends the core capabilities of the FlashSound API to support direct interaction with ActionScript within a SWF. A developer can use the ActionScript extension to enable FSCommands, get and set flash variables or movie clip properties and execute actionscript directly with the TCall( ) method.