Gifsicle manipulates GIF image files on the
command line. It supports merging several GIFs
into a GIF animation; exploding an animation into
its component frames; changing individual frames
in an animation; turning interlacing on and off;
adding transparency; adding delays, disposals, and
looping to animations; adding or removing
comments; optimizing animations for space; and
changing images' colormaps, among other things.

The gifsicle package contains two other programs:
gifview, a lightweight GIF viewer for X, can show
animations as slideshows or in real time, and
gifdiff compares two GIFs for identical visual
appearance.