It's translating to SVG, so there's "just" the script translation overhead, not rendering overhead. I think it's quite practical if maybe not especially useful

It's translating to SVG, so there's "just" the script translation overhead, not rendering overhead. I think it's quite practical if maybe not especially useful given Flash penetration. I wrote a Flash player for the PS2 ~9 years ago now that was fast enough. I'd say that current PCs + jitted JS are faster than that platform.