[evan_]

We're talking about Javascript the language, not individual implementations of javascript in browsers. Any browser could implement screengrab API today, they just haven't. Same for multithreaded javascript. Audio/video/canvas are all things that browsers have implemented, they are not innate features of Javascript.

Also despite what you say you CAN trigger an event (or whatever) inside a loop, it just won't do anything until you're out of the loop. This is because your browser implements javascript in a single thread. There are two easy solutions: Don't use a loop that's going to last for a long time, or use a Web Worker. This is, again, something that browsers have implemented, not a part of javascript. http://en.wikipedia.org/wiki/Web_worker

[dwj]

I didn't mean 'trigger an event', I meant 'spin the event loop'. Unfortunately web workers have too many limitations, and won't work in many situations. And the solution of 'don't use a loop' isn't possible/feasible in certain cases. No point in going into detail here, but basically I am porting a virtual machine to javascript.