With the end of Google Labs, there are many great projects that are coming to an end or relocating to a new home. Luckily, Google Swiffy is one of the survivors.
Earlier this year Google introduced Swiffy, a Google Labs project that could input any Flash animation, and output the corresponding HTML5 animation for it. It makes use of open technologies such as SVG, however it also relies on the fact that the SWF specification has been published.
Swiffy is capable of converting SWF files created by older versions of Flash, best up to Flash 5, and can even convert some ActionScript 2 code.
It goes without saying that a modern browser is needed to play back such content since it relies on features provided by newer standards and thus newer browsers.