https://michaelbach.de/ot/mot-adapt/

Flash is dead, an unfortunate fact of Internet evolution. I never liked ActionScript (the programming language behind Flash when not just using graphical tools), but followed it over three major versions, building 50+ pages on my Visual Phenomena and #opticalillusion site. Now I am slowly converting this to JavaScript (specifically, http://cappuccino.dev). 

This is also the first time I'm using "requestAnimationFrame", a relatively new technique, now available across many browsers, to tie the animation cycle to window updates thus (1) reducing stuttering (hopefully) and (2) reducing browser load by avoiding needlessly high update frequencies. Thanks to Ken for alerting me to this.