Inkscape can be enhanced by Effects. These are scripts or programs that can be run from inside Inkscape. Most Effects require external programs, usually written in Perl or Python.
Many of the included Effects might be of marginal use to the average user. However, much can be learned by examining the code in order to write your own scripts. Look in the
share/inkscape/extensions directory for the code. Note that on Windows, Effects written with Python will pop open an empty console window. This window will disappear when the Effect is finished.
A few Effects are built into Inkscape; they are located in the source directory
src/extensions/internal. Often, an Effect can be used to quickly prototype a feature that may be included ...