Synchronisation. This was a simple example of how you could make animations go on forever in SVG.

<defs> <animate attributeName="cx" from="50" to="200" fill="freeze" id="first" xlink:href="#c1" dur="1s" begin="1s" /> <animate .. id="second" xlink:href="#c2" dur="1s" begin="first.begin" /> <animate .. id="third" xlink:href="#c2" dur="1s" begin="first.end" /> <animate .. id="fourth" xlink:href="#c2" dur="1s" begin="first.end+1s" /> This has no repeatCount: it goes on forever!
Synchronisation