Used this same trick (but with SMIL) for an automotive client back ca. 2004. They wanted their electrical systems' documentation diagrams to be in SVG, with sig

Used this same trick (but with SMIL) for an automotive client back ca. 2004. They wanted their electrical systems' documentation diagrams to be in SVG, with signals being animated in a similar fashion. At the time the only viewer that supported it was Adobe's ActiveX plugin! (Not claiming credit for the trick; AFAIR I found it on a web forum somewhere... wish I remember who invented it)