With the release of Firefox 3, I mounted a private celebration: I went back to using Opera 9.5 as my main browser. This wasn't just perversity. Firefox without its add-ons is clearly inferior to Opera. Firefox with enough add-ons to make it really useful is very much slower. And Opera has one advantage over all the competition which is enough to outweigh all its other faults to me.

I don't mean that Firefox is a bad browser. There's very little it won't do, and many of the add-ons are thoughtful and effective. I still love Zotero, which does citations and bibliographies from web sources and integrates with Word and OpenOffice. For anyone doing remotely scholarly work, this is wonderful. It's worth keeping Firefox around for that one add-on, and I will certainly do so.

There are other valuable Firefox add-ons, too. Piclens is a gorgeous and thought-provoking way of looking at photographs. Adblock is indispensable, and I have written about it before (Drugs and Adblock shouldn't be in the hands of everyone else, May 1 2008). "It's All Text" lets you drop the contents of any text box into a real editor which will correct typos, do search and replace and so on. Tab mix plus keeps tabs in order; other add-ons will turn Firefox into a blog editor or an RSS reader. But almost all these powers come with Opera out of the box. It has no blog editor, but I don't need one. I can't find the equivalent to "It's all text", but I know it has existed. It does the two things that I really need in any browser, which are tab management and ad-blocking, very well indeed. It has a crude but effective note facility which can be synchronised across computers. The bookmarks and the history are both indexed and can be searched almost instantaneously.

Best of all, though, is its mail program. I hated it at first, but I missed it for the whole year that I haven't used it. Opera's mail is unique - so far as I know - in that it indexes everything without fuss and finds it at once whenever you want it. It doesn't organise by folders (though it can) but by searches and by tags. Imagine a sort of instantaneous Gmail that works offline as well. All conversations can be automatically threaded and this suits the way I work much better than anything else.

It's not perfect. It's ugly, and it doesn't do HTML mail. It doesn't integrate well with the operating system. For some these will be insuperable objections, but anyone who just cares about finding and answering their email quickly should give Opera a try.

The contrast between Opera and Firefox is an interesting example of the contrasting strengths of open and closed source. Opera has always been closed source, and commercial and proprietary even though it is nowadays free to use.

The good results of this are obvious. It was innovative, original and responsive to customer pressure - none of these qualities I'd associate with open source. Because its users and its programmers were always distinct groups, the programmers thought much harder about how to please the users - sometimes even before the users knew what they wanted. Opera's excellent mobile phone browser is years ahead of Firefox's project there.

Firefox started with the ambition that a significant proportion of the users would be converted into programmers. In open source the boundary between the two groups is meant to be blurred. The good result is that the browser is very much easier to extend. There isn't and there couldn't be an Opera equivalent to the Firefox add-ons community. The bad result is that the extensions endlessly repeat each other.

Firefox, now that it is an established success, will never run short of programmers, whereas Opera has been held back by a lack of them. The mail program, for example, was truly revolutionary when it first appeared five years ago, but it seems to have been the work of only one man, and he definitely needs help to keep it ahead of the game. But far more projects have been wrecked by having too many programmers than too few.

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