[Niten]

For one thing, IE 8 is arguably a more secure browser than Firefox due to its use of low-integrity process isolation on Windows Vista and 7. It's also more stable than Firefox in my experience, probably because of the way it isolates browser windows into separate processes.

And now IE 9 has a rendering engine that's at least equal to Firefox's. It lags behind Firefox's user interface in some respects (customization, built-in spell check), but it feels much faster, and it doesn't bog down over a long browsing session like Firefox does (again thanks to isolated browser processes – now one for each tab, just like Chrome).

For my part, I still think Chrome is superior to both IE and Firefox for general web browsing, but these days I certainly wouldn't look at someone funny for choosing IE. It may just take a little while for the folk knowledge that "IE suxors!" to catch up to the new reality.

[yesimahuman]

My biggest issue with IE as a browser is that Microsoft's enterprise support priorities are not inline with my innovation priorities. I would rather support faster moving browsers such as Chrome or Firefox.

Supporting IE seems to me to be supporting a project that will be obsolete in many ways soon after launch, and will stay that way for quite some time.

[Legion]

Are you comparing IE 9 to Firefox 4.0, or Firefox 3.6?

[Niten]

I'm comparing to Firefox 3.6; Firefox 4.0 isn't released yet. But everything I've read indicates that Firefox 4.0 will still have a single-process, non-low-integrity process model, with all the security and reliability implications that go with it.

Hopefully Firefox 4 will catch up to the likes of Chrome and Safari (and IE 9) in terms of JavaScript performance, judging by benchmarks on the release candidate, but I haven't seen any indication that it addresses Firefox 3's fundamental design weaknesses. Of course, feel free to correct me if I've missed something in the release notes somewhere...

[Legion]

Understandable, but still, when it comes to comparing how IE 9 stacks up to "Firefox" on rendering engines and memory usage, it doesn't seem particularly meaningful to compare the brand new IE 9 to the old Firefox just because IE 9 released a single week before the next major revision of Firefox is slated to. Not that you were writing a New York Times article here or anything. :)

I certainly understand your other point about the single-process design.