For years, Microsoft's Internet Explorer has led the pack, though Mozilla's Firefox and Google's Chrome have made some inroads.
According to recent Net Applications' data, Internet Explorer had about 59.3 percent of the market in October, while Firefox had 22.9 percent and Chrome about 8.5 percent. Apple's Safari and Opera had 5.3 percent and 2.3 percent respectively.
"Based on conversations over the years with a lot of analysts and browser experts, people are very hesitant to change browsers. That's one of the reasons why Internet Explorer enjoys a majority of users worldwide," said Gregg Keizer, a Computerworld reporter who covers Web browsers, security issues and other related topics. "In large part, because they just don't see a need or don't want to or don't know how to change a browser. They may not even be aware that there are alternatives."
Internet Explorer, which comes bundled with Microsoft software, is the browser of choice for businesses and those who don't want to deal with installing a second browser, he said. It's a fine browser, he said -- but given its massive market share, it's often the first target of cyber criminals.
"The downside for Internet Explorer is that, historically, it's had the most security problems," Keizer said. Microsoft does regularly release patches to keep up with vulnerabilities but security can still be a concern. He also said that it's slower than other browsers but, since speed is measured in milliseconds, it's not something users would often notice as they surf the Web.
For those willing to change things up, Mozilla's Firefox has consistently presented a second solid option.
"That browser, I think, is a really good choice for people who like to customize because it has the largest number of extensions or add-ons that are available," Keizer said, adding that thousands of options exist for Web users who want to add gaming, commerce, social and all kinds of other shortcuts to their browsing experience.
Google's Chrome still has yet to break into the double digits when it comes to market share, but Keizer said it's gaining momentum.
"That's a browser that I think a lot of people are picking up because it's very fast, it's very clean and it has name recognition where Mozilla's Firefox really doesn't among the mainstream," he said.
Safari is bundled with Apple products but it and Opera, another free browser, haven't had much success breaking into the mainstream.
Keizer said the social browser Flock has struggled to attract users, which doesn't necessarily bode well for RockMelt. But he added that Facebook's growth could mean good things for the upstart browser service. Not only are millions of users accustomed to communicating on Facebook, they're getting more and more used to an entire Web experience built around sharing.
"I think it's got a lot of potential," he said. "I don't know how it's going to play out long-term, but with half a billion users-plus on Facebook, there's possibly a market for a browser that specializes in that."