Why must Firefox and Opera fight?

Why must we fight?
Can't we at least just put it off until we distroy Internet Explorer?
Come on! Lets team up and distroy the true evil, instead of bickering all the time about which one is better...

Firefox is not a jack of all trades, master of none that Opera is.

Yeah, so... why is Opera smaller?

Without that, stock for stock, Firefox is equal to Opera.

Uh-huh: IRC, email, magic wand, notes, mouse gestures, links list, reload-every, RSS, fit-to-window, sessions, and even voice if you want it. These are just the things that I use and am aware of.

Of course, this ignores all the little gui nicities that Firefox doesn't have. And try using the two of them on on a slow machine to really see the speed difference. I haven't had Opera cause major swapping after leaving it up for several days either.