Sourcehttp://irae.pro.br/lab/canvas_pie_countdown/

CommentsWith HTML 5 canvas element you can draw dynamically on your webpage using javascript.
This example draws an animated pie to illustrate that canvas element has a transparent background by default.

Saving the generated canvas graphics

The graphics can be saved (at least in Firefox) by right clicking and save as png file.

This page also uses explorercanvas javascript library which adds canvas features to MSIE.