Todd Bishop of the Seattle PI speculates on whether the Mozilla crew is thinking of spinning off a Firefox PC operating system. It’s pretty thin speculation, and I’d dismiss it out of hand, at least in the guise of a built-from-the-ground-up OS. It takes years to build an OS kernel from scratch.
Now, it’s certainly possible that the Firefox folks and their good buddies at Google could pick a Linux distro, slap some app software into it, and make it available as a CD or even an OEM install. But it’s hard to imagine how yet another Linux is going to make much of a dent in the Microsoft/Apple market for consumer operating systems.
Ed Bott 
A Linux distribution where all of the software was built with the same rigor and to the same specs as everything else Mozilla has put out would be outstanding. But I suspect it’ll never happen.
And in true Firefox tradition, it will be slow to boot. 😦
The reason why Firefox is slower than Internet Explorer when it comes to booting is that part of IE is already loaded at the startup of Windows. It’s not really a fair comparison.
It doesn’t matter what causes the lag time. Slow is the operative word.
Put firefox in your startup group or as a service.
When starpup is done, it’s faster then explorer; just one click away.