Are there ways to remove the sliding and fading effects from Firefox as an end user when I visit web pages that use such javascript effects?
When some element is inserted into the DOM, the elements after it are slided down. This is a graphical effect, that is very time and bandwith consuming when someone is viewing over a remote connection (terminal server, citrix, remote X, nx) It would just be OK to see the page in it’s new shape without the sliding and many intermediate states.
Maybe there is a setting for this already (about:config)?
There are greasemonkey scripts for most popular sites to streamline the interface and eliminate such annoyances. There is no way to disable it in general because it is not a single feature but an emergent result of a combination of otherwise benign features.
To clarify that last bit… Each individual javascript function used for these animations (that is, timers and element size/placement manipulation) has legitimate uses. It is only the combination of them that is a problem, and they can be combined with other operations in myriad ways. Some sort of heuristic could possibly identify likely-annoying animations in websites at large, but individual fixes targeting specific sites (or site frameworks, all jquery sites use the same animation code, etc) will be far more effective and efficient.