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.