There's already a very good binary encoded vector graphics format, which also supports animation among other things --- SWF. The descriptions in this specification actually look somewhat like it.<p><i>The original SVG is 96,719 bytes large, while the optimized one is 85,806 bytes large. When converted to TinyVG, the file shrinks to 27,522 bytes. This means we only have 32% size of the optimized source data.</i><p>I have a tiger.swf which is 21381 bytes, and since there's another comment here about gzip'ing them, tiger.swf.gz turns out to be only 17296 bytes. In conclusion, I think a subset of SWF, of which much existing rendering code is available, will provide much better efficiency and compatibility than this.