gifsicle

Gifsicle is a command‑line utility for processing GIF image files. It can combine multiple GIFs into a single animation, split an animation into its individual frames, and modify frames by adjusting delays, disposal methods, looping, interlacing, transparency, colormaps, and comments. The tool also offers space‑saving optimizations, as well as geometric operations such as flipping and rotating images.

Companion programs extend its functionality: gifview displays GIFs on X displays, supporting both slide‑show and real‑time animation modes, while gifdiff compares two GIF files for visual equivalence, useful for testing other GIF‑manipulation software. All programs include manual pages for reference.

The package builds on UNIX systems with a standard configure‑make workflow and can be compiled on Windows using Visual C or Borland C++ makefiles. Gifsicle is released under the GPL‑2.0 license, with an optional alternative permission for non‑open‑source redistribution, and has been maintained since 1997.