As of release 3.0.4, Firefox is available in Esperanto!
Language packs at mozillaZine has some more info about language, locale, profiles, and commandline switches. And instead of using a locale switcher, you can surf to about:config and change the value of general.useragent.locale to the desired language code (If you make a mistake or haven't installed the relevant language pack, Firefox will default to the langauage of the version you installed).
This page used to be mostly about Opera, praise and tips and tricks and such. I was an Opera fanatic around the turn of the millennium, and a registered user. It was small, fast, (allegedly) standards compliant, and had many handy features not found in other browsers. It was also buggy and crashed a lot, but we fans loved it anyway. But then Opera got big and bloated like the other browsers, changing to be more like them in a grab for market share I guess. And I found that its standards compliance wasn't much better than that of the others, in some ways worse; I guess standards compliant for Opera just meant no extensions. (Sometimes their "compliance" seemed more like a misunderstanding of the English language standards documentation, noted in some of my email exchanges with them!) So I stopped using it as my development testbed, and then used it less and less for casual browsing too as time passed. By the time I removed Opera from the last machine on which I had installed it (April 2005), it still hadn't become reliable enough for me to use when I absolutely needed something to work (online banking and shopping, for example)...
So that's why this page is pretty empty now. I cleared out all my Opera praise and rants, and tips that mostly didn't matter anymore. I did give Opera another chance later anyway, when I needed an IRC client. Worked okay, but then I dumped it again. Used Internet Explorer for a while, then switched to SeaMonkey, then to Firefox after I overheard some coworkers talking about Firebug...
And I still like Firefox for the extensions, but tried Chrome when it appeared. At first I didn't like Chrome; seemed like one of the things that made it "faster" was that it gave up too soon! For example, pages would stop rendering with images incomplete, just the top third of each displayed. But they fixed that, and I started using Chrome for more and more for general surfing, switching back to Firefox when I needed some particular extension...
Chrome 69 introduced a major misfeature known as "identity consistency". Before version 69, bookmark synchronization was separate from Google's online services; I entered my password for synchronization and never had to think about it again. I could log in and out of any other Google services without affecting synchronization. With version 69, synchronization pauses (logs out) when I log out of any Google service, Gmail for example. If I re-enter my password for synchronization, I've then unintentionally logged back into other Google services, so, for example, if I go to Gmail it opens up for that account without requesting a password! YouTube will try to open with the same account, and I can't use a different account unless I log out of synchronization. This behavior could be overridden by disabling the "Account Consistency" chrome flag, but version 70 broke that workaround. For some details, see Google secretly logs users into Chrome whenever they log into a Google site, Chrome Sync signs out when logging out of Gmail, Issue 882243: Chrome 69 breaks multi-sign in, and Issue 889366: Chrome changes my secondary Google account to the default one. Google says that this will not be fixed because it is behaving as intended. So now I'm revisiting Firefox. I like and am comfortable with Chrome's bookmark manager and synchronization, so for now I'm using Google Chrome for general surfing and non-Google services, and Firefox for Google services. Isn't that ironic?