The Interpolation panel gives a quick access to interpolation options located in Fireworks Preferences.
Installation instructions
Drop the .jsf or .swf file into the Commands (or Command Panels) folder then run the command or if you have a mxp file, double-click the mxp and installation is automatic.
Requirement
Fireworks MX and higher
Tutorial
Preferences.
Figure 1: Interpolation options in Fireworks Preferences
Interpolation interface
With the interpolation command you can switch from an option to another one very rapidly without having to go to the Preferences. A huge time saver!