Long-time Mac users probably remember the day when Microsoft Internet Explorer and Netscape Navigator were the only games in town. With Mac OS 9 and the early days of Mac OS X, IE was the lean, mean, speed-machine; while Navigator was continuing its fast slide to irrelevance. But with OS X’s Unix underpinnings, and its sleek new GUI, it wasn’t long until developers started porting old browsers, or releasing all new ones to run on Apple’s shiny new OS. One of the earliest non-MS/Mozilla browsers was OmniWeb. It was easily faster than most anything out there, had a slick interface, and boasted features few other browsers offered at the time, such as tabs on the side, per-site preferences, built-in ad-blocking, and more. Due to Microsoft’s barely-an-effort port of IE to OS X, and Netscape Navigator suffering from never-ending software bloat, the time was right for other vendors to make their move. OmniWeb’s popularity exploded, and with it came a (welcome) blistering onslaught of Web browsers available for the Mac.
Mac Web browsers
Firefox
In November of 2004, Mozilla released Firefox 1.0, and browsing the web on the Mac has never been the same. Tabbed browsing and the ability to add features to the browser via extensions quickly made Firefox a popular alternative to IE, Navigator and OmniWeb. It was fast, and free — two things that helped make it what it is today, which is the second most popular browser in the world. 
OmniWeb
Despite its best efforts, OmniGroup simply never stood a chance. Charging for a browser was, and never will be, a popular or accepted idea. Despite this “deal breaker,” and only modest development the last few years, OmniWeb remains a pretty decent browser. It’s relatively fast, and still offers a few features not found natively in other browsers. In a classic case of too-little, too-late, OmniWeb is now free. 
Safari
Apple generally focuses on speed, usability and a beautiful interface with its software. The release of Safari in mid-2003 changed the landscape of Web browsers on the Mac forever. A sleek and simple interface and raw speed covered the fact that the browser was actually quite under-featured. To this day, Safari still offers no official way of adding features (though there are several highly-popular plugins that use a workaround), but it continues to be the fastest browser available for Mac OS X. Safari has enjoyed a high adoption rate, due to the fact that it’s the default browser, and the only one installed on any new Mac. 
Camino:
Due to Mozilla making all their code open-source, a number of browser developers have chosen to base their browser off the very same code that Firefox employs. The most popular of these to date has been Camino. With its native OS X interface and a speedy rendering engine, Camino is a popular choice for those seeking alternative browsers. The only real draw-back to Camino is that despite the fact that it’s basically Firefox under the hood, it does not support additional features via extensions. 
Flock:
Billed as the “Social Media Browser,” Flock has gained quite a following among Twitter, Facebook, RSS, YouTube and Flickr users due to those services’ integration into the browser. Flock is another Mozilla-based browser, but adds a much more sleek interface, and numerous social media doo-dads. While I’ve found the browser to be speedy enough for most users, its biggest failure is the very set of features that makes it what it is. The social media features are all very basic in nature. If you’re heavily involved in social media, you’ll most likely find the features too lacking to get any value out of. 
SeaMonkey:
Though the Netscape brand has long since been retired, the original Netscape Navigator Application Suite lives on in the form of the open source SeaMonkey. The Mozilla Ghecko rendering engine powers this suite of applications that includes a browser (Navigator), Email and Newsgroup reader (Mail & Newsgroups, similar to Mozilla Thunderbird), HTML Editor (Composer), and an IRC client (ChatZilla). Because the suite is all based on open source code, SeaMonkey is still under development. But most users will find that SeaMonkey underwhelming compared to the other options out there. 
The rest:
The latest entry into the Mac browser market is perhaps going to have the largest impact. With the seemingly endless engineering brain-trust and virtually unlimited marketing power, you would think that when Google finally releases Chrome for the Mac, it’s going to make a big splash. As with all Google products, Chrome will feature a sparse GUI, and superb integration with Google’s online app offerings. Chrome is in early beta stages, so it’s difficult to tell how well it will perform. But with Google backing it, I can’t imagine it being a failure by any stretch of the imagination. There are several more options out there. Opera is a popular Windows browser that has a Mac version. In my experiences with it though, it suffers from feature-bloat like no app I’ve ever seen. It simply has too much in the way of customization! iCab has been around since before OS X. You’ve probably never heard of it, and there’s a reason for that; it’s lackluster at best. Then there are newcomers like Demeter and Shiira trying to break-in to the market. They’ve got an uphill battle ahead of them. What I fear is that while we expect more and more from our Web browser with every update, we are quickly approaching the very problem we had that brought on all these options to begin with. Feature-bloat. With Firefox and Safari being the only two guaranteed success’, one has to wonder if we really “need” all these offerings. Does having so many options with their unique features serve to do nothing but muddy the water, and force the more popular browsers to add more and more features, thus adding to the bloat? In short, I have to wonder; with all these browsers available to us, “are we there yet?”