G'MIC plug-in for GIMP.

GIMP is an acronym for GNU Image Manipulation Program and it has many capabilities.
One best feature is the plugins system. Plugins may be stored in different locations depending upon your distribution.
The author of G'MIC plug-in tell us: The G'MIC plug-in for GIMP proposes a set of various filters to apply on your images, including artistic effects, image denoising, and enhancement algorithms, 3D renderers, etc.. It is a quite large plug-in, integrating a lot of different effects.
You can download the G'MIC plug-in from here.
Unzip the file and go to the folder where is the gmic_gimp file.
Use this command to copy the file in the plug-ins folder.

$ cp  gmic_gimp ~/.gimp-2.6/plug-ins/

Once you have installed the plugin just restart the GIMP.
The G'MIC will work just if you have opened an image.
You can find it on menu: Filters-> G'MIC... Also, the G'MIC plug-in has available 284 filters.