Before you create a Dreamweaver extension, visit the Macromedia Exchange website at www.macromedia.com/exchange to see if the extension you plan to create already exists. If you do not find an extension that meets your needs, you then perform the following steps to create the extension:
Determine the type of extension you want to create. For more information about the extension types, see Types of Dreamweaver extensions.
Review the documentation for the type of extension you plan to create. To become familiar with creating that type of extension, it's a good idea to create the simple extension example in the appropriate chapter.
Determine which files you need to modify or create.
Plan the user interface (UI), if any, for the extension.
Create the necessary files and save them in the appropriate folders.
Restart Dreamweaver so that it recognizes the new extension.