The Extension Manager 1.7 is an application that is part of the Fireworks 8 and Flash 8. Extension Manager lets you easily install new programs called "extensions" and keep track new ones, wich you must download it from the Macromedia Exchange site.
You can create an extension that be compatible with Macromedia Fireworks or Macromedia Flash; in this case, your extensions can be shared using Extension Manager 1.7, for that you just need submit this extensions and this will be packaged automatically.
Extension Manager 1.7 includes support for Dreamweaver 8, Fireworks 8, and Flash 8; many new features have been added to support extensibility within the Macromedia Suite Studio 8.
After you install new versions of Dreamweaver, Flash or Fireworks you do not need to re-install Extension Manager 1.7 . The first time you launch Extension Manager 1.7, it searches for previously installed extensions and displays them on your screen. The extensions that Extension Manager 1.7 application find are disabled by default. You can enable any of those extensions that be founded by Extension Manage 1.7 clicking the On/Off checkbox.