FlashFirebug

FlashFirebug (now Flash Debugger) gives you the ability to debug any AS3 Flash on the web. Inspect the DisplayList, change properties on the fly and see the warnings, errors and traces directly in the extension. Use the inspector to hone in on elements, transform objects on the fly and use the console to run AS3 commands.

Properties

The property panel displays all properties for the selected object including the data type, value and accessibility (i.e. readonly, read/write). You can modify the properties on the fly and the panel helps you by listing the allowed constants for some fields and allowing you to increase and decrease numeric values using the keyboard.