Ars Technica said yesterday that Mozilla needs to make 64-bit Firefox on Windows a high priority. I agree with this completely. With web browsers, you can’t have too much security, and Firefox on Windows is a big target.
There are issues with going 64-bit, as the article states, but there are workarounds. One phrase I’ve heard frequently is that going 64-bit doesn’t necessarily mean better performance. And yes, that’s true, though there are also performance benefits to not running out of memory when you have a lot of tabs open. But address space randomization is something we need, and it’s worth giving up a little bit of performance in order to get that.
I find it curious that Mozilla is concerned about the size of the userbase, and thinks that not having a 64-bit browser on Windows isn’t affecting the size of that userbase. Like the Ars article says, there are more 64-bit Windows users out there than there are Mac and Linux users combined.