STR: 1. Load http://kripken.github.io/boon/boon.html 2. Let it automatically play, notice frame rate is very smooth 3. Open another tab, write "mail" in the title bar and hit enter to start a search. 4. Return to the doom tab, and notice that while the spinner for the other tab is active, rendering is very sluggish in doom. It gets to 1fps or so on my machine. (5. After a while, rendering should be ok. Go to the other tab, hit reload, and return to doom, to see the effect again.) In a session with many tabs, it is common to have other tabs do something now and then, making demos like this one unusable.