Well, you can do a setTimeout with just 1ms delay or use window.postMessage when it's available. I must admit though that it is kinda counter intuitive how "swa

Well, you can do a setTimeout with just 1ms delay or use window.postMessage when it's available. I must admit though that it is kinda counter intuitive how "swapbuffer()" is called only implicitly when your top level function finishes. But it doesn't work too bad. I found that the GC is usually not a problem in any browser when you want to animate something smoothly in <canvas>. Plugins in FF (like Firebug or the Echofon Twitter Client), or things like an AJAX request however can result in stuttering animations. Can you elaborate your statement about "(...) dealing sanely with off-screen canvases"? Do you mean things like double/tripple buffering? Edit: For the record: the particle animation runs extremely smooth in Safari on my 2 year old Macbook Air. As far as I can tell, Safari on OSX currently has the most "direct" and efficient way to draw Canvas elements.