Gifsicle is a command-line tool for creating, editing, and getting information about GIF images and animations.

contains gifview a great slideshow tool for multi-frame gifs.

A nice blog post about Delaunay triangulation and Voronoi tessellation of a sphere.

Very nice interactive JavaScript animation that shows the triangulation and the tessellation as a function of some paramenters.

Animator5D - Very simple-to-use framework for rendering 5-dimensional animations (x, y, z, time, some color value) as an animated gif. This requires ImageMagick to combine the frames, but you can still render them without having it installed and just combine them with some online gif maker.