Tested with GNU IceCat Rated 5 out of 5 stars
I replaced Microsoft Windows on my TabletPC with Gnewsense GNU/Linux and was pleased to see that the default web browser ("IceCat") works with "Grab and Drag" just as if it was Firefox. (Which it should, since it's based on the same source code as Firefox.)
By the way, to respond to the guy (ander) who was asking, "What's the point", the answer is touchscreens and momentum. "Grab and Drag" makes touchscreens, like my TabletPC, work the way we've come to expect and it's especially handy when I have my tablet screen flipped so that I have no keyboard.
One thing that's missing from the description of this plugin and from most of the reviews is the awesome feature of "Grab and Throw", which this extension calls "Momentum". Say you want to scroll quickly through a page, you just simply release the mouse while you're dragging and the page keeps moving. When you want it to stop, just click the mouse anywhere in the page to "Catch" it. (Of course by "mouse" I actually mean your stylus or finger or other pointing device.) This is so handy and versatile, I actually disable the "flick" gestures which work like page up and page down so that I can scroll the screen even more quickly.