I first became aware of Opera in the late 1990s and I tried out version 3.5 and 4, but neither really made much of an impression. Plus, at the time, Opera was trialware... there was a free trial, but after that ended you needed to purchase the software if you wanted to keep using it. Starting with version 5, Opera became free, but it was ad-supported, and there was this big, honking banner ad built into the browser. On the other hand, Opera 5 was also the first browser to implement mouse gestures, the most addicting browser feature I've encountered (more on this later). As time went on and other browsers emerged, Opera finally relented and released a completely free browser in 2005. I've used Opera as much as possible since then, though I've occasionally used other browsers for various reasons. The biggest complaint I've had about Opera is that some websites don't render or operate correctly in Opera, thus forcing me to fire up IE or FF. This complaint has lessened with each successive release though, and Opera 9.x seems to be compatible with most websites. The only time I find myself opening another browser is to watch Netflix online movies, which only work in IE (more on this later). Opera is certainly not a perfect browser, but each release seems to contain new and innovative features, and it has always served me well.
The only browser that has really compared with Opera is Firefox. It's based on the open source Mozilla project, which began in 1998 as a replacement for the Netscape 4.x browser (which was badly in need of an overhaul). Unfortunately, development of the open source browser was slow going, allowing Microsoft to completely dominate the market. However, version 1.0 of the Mozilla Application Suite (which included more than just a browser) was launched in 2002. It was bloated and slow, but the underlying code (particularly the rendering engine, named gecko) was used as the base for several new projects, including Firefox. Firefox 1.0 was released in late 2004, and has been picking up steam ever since. It's the first browser to challenge IE's dominance of the market, and it's also far superior to IE. The current version of Firefox is mature and stable, and a new version (3.0) is on its way that will supposedly address many of the current complaints about FF.
Of course, these are not the only two browsers out there. Internet Explorer is notable for it's widespread adoption (during Q2 of 2004, IE had an asounding 95% share of the market). IE isn't very good compared to the competition, but its one virtue is that most websites will load and render properly in IE (and some websites will only work in IE). As a web developer, I have an intense dislike for IE, as it has poor standards support and is generally a pain to work with (especially IE6). IE7, while an improvement in many ways, also features some bizarre interface changes that make the browser less usable.
Also of note is Safari, Apple's default browser in OS X. Based on the open source KHTML engine (which runs KDE's Konqueror, the primary open source competitor to Mozilla/Firefox), it implements many of the same features of Opera and FF, but in a simple, lightweight way. I've never been much of a fan of Safari, though it should be noted as a valid competitor. It's a solid browser, fast and clean, but ultimately nothing really special (perhaps with more use, I would be won over). Finally, there are a number of other smaller scale or specialized browsers like Flock (which has many features tailored around integrating with social networking sites), but nothing there really fits me.
So the most realistic options for me are Opera and Firefox. Both have new browsers in Beta (or higher), but I'll be primarily using the current releases (Opera 9.27 and Firefox 184.108.40.206). I've played around with Opera 9.5 and Firefox 3 RC1 and will keep them in mind. For reference, I'm running a PC with Intel Core 2 Duo (2.4 GHz), 2 GB RAM, and Windows XP SP2.
- Default/Native Features: These first two criteria are tricky because they reflect the underlying philosophy of the two companies. Opera cleary has the better feature set out-of-the-box. Firefox is no slouch, of course, but it can't compete with the quality and quantity of Opera's default feature set. Both browsers have strong standards support, tabbed browsing, popup blocking, integrated web search, and other standard browser features. Now here's the tricky part. Opera has several features that FF doesn't. However, FF has one big feature that Opera doesn't, and that's their Extensions and Add-Ons (more on that in a moment). Opera does have a few major pieces of native functionality, like Mouse Gestures and Speed Dial, as well as other, smaller touches, like paste-and-go and the Trash Can. Now, the inclusion of all these features by default has its disadvantages as well. Especially when you consider all the features that aren't very useful. Opera includes an email client (which is decent except that I don't use it anymore), integrated BitTorrent support (which is awful and should be disabled), and the particularly weird Widgets (which are near useless, more on this below). This leads to the frequent claim by Firefox supporters that Opera is "bloated" with extra features. I suppose that's technically true, but then, Opera is also a smaller download (Opera 9.5b2 is 5,117 KB versus Firefox 3RC1's 7,317 KB), takes up less space on the HD (Opera at 6.02 MB versus Firefox at 22.6 MB, though FF also has Add-Ons), and has a lower memory footprint. Call it bloated if you like, but that doesn't mean that FF isn't bloated too (honestly though, this is a quibble - both are way, way better than IE).
- Add-Ons/Extensions/Plugins: While Firefox does not have many features installed by default, it does have support for Add-Ons, and there is a huge community of developers and a large number of useful Add-Ons available for download. Many of the things Opera does natively can be replicated using a FF Add-On (in my experience, the Add-On is not as good as the native support, but passable). In effect, Firefox actually has more features available than Opera because of these Add-Ons. Now, this philosophy also has its drawbacks. First, you have to seek out and install each Add-On, and second, some Add-Ons are poorly written and cause performance problems within FF. In the end, though, the usefulness of the Add-Ons outweigh the negatives. Opera remains stalwart in its refusal to implement any sort of plugin system (beyond the rudimentary, circa 1995 Netscape-like system they have now), though they did launch something called Widgets, which are pretty much worthless. Opera's reasoning for not supporting extensions is sound, but also limiting:
Opera does not support third party extensions. Opera has rather incorporated the most useful and popular features in its browser and holds itself accountable for the functionality of these features. With integrated features rather than extensions, users are not subjected to the vulnerabilities of extensions created by third parties, which may or may not go through a verification or testing process. With the largest Web browser development lab in the world, Opera ensures that all of its features are smoothly integrated, tested and ready for the user.This is certainly one way to approach the situation, and it's also probably the reason why Opera's native functionality works better than Firefox's Add-Ons, but again, it's quite limiting. More than anything else, Extensions are what would make me switch from Opera to FF. Opera is very innovative and they were the first to implement many features into their browser (for instance, tabbed browsing, mouse gestures, and more recently, speed dial), but even when Opera does manage to implement a brand new feature not in FF, it doesn't take long for someone to put together an Add-On to duplicate the functionality. I'll talk a little more about my favorite extensions as we go. Again, the positives of having an open system for third-party extensions far outweigh the negatives.
- Other Customization: Both browsers are highly customizeable and powerful. The interface customization abilities are more extensive in Opera and their Theme manager is easier to use, but Firefox can generally follow along, though sometimes they need to rely on an Extension to allow customization. I don't do a whole lot of advanced configuration in either browser, but both browsers have a way to configure various preferences (beyond the basic options in the menu), etc...
- General Web Browsing: There are a lot of elements to this that will be separated out (i.e., Mouse Gestures, speed, performance, etc...), so what this amounts to is how well each browser loads pages. Since Opera has never commanded more than a few percent of the browser share, most web development doesn't take Opera into account. In the past, this meant that many pages did not look right or operate correctly in Opera. As time has gone on and web standards have become more prevalent, Opera has improved considerably in this respect (well, technically, Opera has always been relatively standards compliant, it's just that the standards are being used more these days) to the point now where I very rarely need to open a different browser. However, there are still pages that render poorly and would look better in other browsers and a page I use frequently, the Netflix streaming video functionality, won't work in Opera. Of course, it won't work in Firefox either, but Firefox has one of those crazy Add-Ons called IE Tab which loads an instance of IE inside Firefox's tabs (meaning that you don't have to exit out of Firefox or fire up a separate IE window). Firefox has captured around 15% of the market and is a favorite of the web development community (see next bullet for more), so it has much better support amongst websites. Opera still lags behind because of its small market share, to the point where even Internet software giants like Google don't launch applications with strong Opera support (for instance, every time Google Reader upgrades their interface, it stops working in Opera for a few days while the Google developers scramble to issue a fix).
- Mouse Gestures: This is probably the most important piece of functionality a browser must have for me. Browsing the internet is a mouse intensive activity, and Opera realized early on that providing this functionality would drastically improve the browsing experience. Opera has native Mouse Gestures support, while Firefox has an Add-On (actually, it has several, but only one of them is worth its salt) that provides similar functionality. However, Opera's functionality has always felt smoother and easier to use. The FF Add-On is a little buggy, the browsing experience is a little rougher, and it seems to be easier to screw up a gesture. I think part of this is that Opera has more caching enabled by default than Firefox, which leads to a more seamless experience when browsing. I'm sure there are ways to make FF more responsive, but I haven't played around with it (and Opera is fantastic by default). I might not be representative of the general internet population, but I think this is one of the most useful and important features a browser can have, and Opera's implementation is just plain better.
- Web Development Tools: Part of my job requires frontend web development, and Firefox unquestionably has the better web development tools. The Web Developer Toolbar and Firebug tandem is difficult to beat. Opera's latest revision of their developer tools, called Dragonfly, is an impressive leap forward and requires some more inspection, but my initial impression is that they still have a ways to go before they catch up with Firefox's Add Ons.
- Speed: Opera is often the winner in various benchmark tests, including this relatively old but thorough comparison of browser speeds (it's been updated a few times and has Opera 9 and FF 2, but is now retired and does not contain stats for the latest releases). Similarly, spot-checking various other benchmarks seems to further indicate Opera's speed. Then again, some initial reports of FF3 seem to indicate an improvement. As always, you have to take these sorts of benchmarks and reports with a grain of salt. My subjective perception of speed is that Opera is faster, but I haven't used FF3 very much, and I'm also not sure how much of that speed is due to caching settings.
- Performance: This one seems to be more tricky. In my admittedly arbitrary and unscientific test, I opened 10 tabs of commonly visited websites in both browsers. Opera was using ~99 MB, while FF was using ~150 MB. (Sites used include Kaedrin Weblog, CBS Sportsline's Fantasy Baseball LiveScoring page, GMail, Google Reader, Wikipedia, IMDB, and a few others) It's worth noting that Firefox has always had complaints about memory usage, especially when you have a lot of tabs open. In some cases, memory issues were traced to malfunctioning Add-Ons or plugins. I've seen other benchmark tests that have closer results and apparently FF 3 has made massive improvements in this area. In my own subjective experience, FF tends to bog down, especially when I have many tabs open, so I'm going to give this to Opera, but if FF 3 works out the way everyone thinks, this may be up for grabs. I'd like to do some more detailed and formal tests on this one though (perhaps later this week).
- Intangibles: As I've already mentioned, I primarily use Opera to browse, so I am obviously biased towards Opera. I suppose there's also something to be said for rooting for the underdog, though when it comes to usability and performance, that shouldn't matter (and really, it doesn't - Opera is a genuinely great browser). And finally, Opera is more innovative than any other browser. They had tabbed browsing years and years before anyone else, their implementation of Mouse Gestures was revolutionary (for me, at least), and more recently, Speed Dial has become a favorite of mine. Their advances small interface issues (like the Trash Can or Paste-and-Go) are rarely noted, but are very useful (enough so that FF has had Add-Ons created to replicate the interfaces). The fact that Firefox can do all of these things doesn't mean they would have come up with them first, and I suppose that's worth mentioning. On the other hand, Firefox is an open source project (there is some controversy about that, but it's still better than Opera) and their philosophy of Add-Ons allows for a much broader range of browser capabilities and customization. In general, I prefer openness to closed systems, so there's another point for Firefox. It's also worth noting that Firefox's market share has been steadily increasing while Opera's has been decreasing (and when your high point is around 2.5%, that's not saying much). Opera has made a name for themselves in the embedded market (i.e. it's on lots of cell phones and other hardware (like the Wii)), so they won't be going away anytime soon, but it seems like Firefox is moving faster now. This is a really close one, but I'll lean towards Firefox because it seems to have a brighter future.
So what does the future hold? If Opera continues to lose market share and doesn't find a way to account for the extensions of Firefox, it's going to be in real trouble (they seem to think their Widgets system will do this, but it really won't). Honestly, if FF 3 really does solve their memory problems, I might even be switching over that soon.