For example Gmail works with Opera if I mask it as Firefox, which is silly.
Weird, GMail 2 works just fine here without any masking (maybe Opera is doing some black magic behind the scenes?)
The thing is that, considering the issues Opera had as lately with many sites, and the improvements coming with Firefox 3, I was telling myself I would end up coming back to Firefox after some years, yet Opera 9.5 and Firefox 3 came out and I find myself using Opera more than before (I even forgot about the "Open with" submenu). Maybe it's because of my Internet habits that lead me to Opera-compatible sites, which rarely are using AJAX, or if they are, run without issues. It should be said Opera's compatibility has increased as lately (GMail being the prime example), and I'm confident it will get even better with time (yeah, I'm repeating myself over and over :)). Or they sue Google, and set things straight out off the courts ;D
In any case, I was accustomed to use Firefox or Internet Explorer as needed, and well, it seemed natural to me (although I loathe to use IE for anything
), and so I cross-browsed (heh, new term) without problems. These days, I fire, errr, Firefox, when I have closed Opera with tons of tabs open, and it's such a annoyance to launch it again, and wait for the sites to load, or just if I need to do something in a incompatible site. IE, only for Windows Update, in the rest of the Internet, I feel dirty using it :D
While it's true that I could replicate Opera in Firefox using extensions, I never saw the point in doing that when I could be using the real thing (and I tell you I thought about doing it a few times already). And yet, some things are impossible to duplicate.