Err, if it is not compiled then it's not shipped as part of the package that you download. The point is that Mozilla can't distribute the source code so there is nothing for you to compile when you press that OK.

Webkit doesn't support anything. They have the HTML5 video tag parsing, and everyone who uses Webkit gets to "bring their own codec." Apple uses Quicktime, webkit-gtk uses gstreamer, Chromium uses ffmpeg (shipped with H.264 and Ogg on Chrome, only with Ogg on Chromium).

But will they? I don't think they are going to ship with gstreamer support anytime soon. And that leaves Windows and Mac; DirectShow on Windows XP doesn't have support for H.264.

Hah, that's hilarious. When hell freezes over.

The "most common host platforms" being referred to are Windows XP and Windows Vista. That's 80% of Firefox's userbase. Do you really think Microsoft will be adding new features to a 8 year old Windows version they are trying desperately to get people to move away from?

Mozilla decided not to let you have an addon that has an exploitable security hole. I don't find that annoying.

First you might find it hard to get that dream of Firefox extensions working in Webkit, since every extension is written in XUL which is not in Webkit. And why the heck do you want less competition in the browser area?? IE isn't really supplying competition, a browser war between them and Webkit sounds horrible. What we have right now is so much better than that boxing match. Keep in mind that Firefox has double the market share of all Webkit browsers put together - and also that a "standards centered philosophy" that just one rendering engine implements could also be called "proprietary" (ie. IE's Webslices are technically "open standards" but nobody would call them that).