What on earth does that site try to do with JS? When I open it in Firefox (43) on an old low end laptop running Ubuntu (15.04) it completely freezes the whole s

What on earth does that site try to do with JS? When I open it in Firefox (43) on an old low end laptop running Ubuntu (15.04) it completely freezes the whole system (had to shutdown with the power button). With NoScript on it works fine.