GraphvizAnim is a tool to create simple animated graph visualizations; it is just a proof of concept, aimed mainly at teaching purposes. It is based on Graphviz for the graph rendering part and on ImageMagick for the animated gif generation. You can run the heap sort animation on-line using binder. A graph animation is just a sequence of steps, a step is in turn one or more actions such as: add, hilight, label, unlabel or remove a node, and add, hilight, or remove an edge. Animations can be built by invoking suitable methods of a gvanim.Animation object (in a Python program), or by parsing a simple text file (that, in turn, can be generated by a program in any language).