A MIAMI teenager is basking in the glory of helping to create a new internet browser at 17 that is now challenging the grip of Microsoft, which once held a virtual monopoly on web surfing.

Computer analysts say that Blake Ross’s browser, Firefox, is a faster, more versatile program that also offers better protection from viruses and unwanted advertising.

Not only that, the system is offered free over the internet and its codes and technology are all accessible as an “open source” programme. Firefox has already been downloaded by an estimated 15 million users since its launch in November, making it the world’s second-most-popular browser.

Industry experts have dubbed the new software “Microsoft’s worst nightmare”, according to the technology magazine Business 2.0. It hailed Mr Ross, now 19, as a software prodigy. He is also a talented pianist and “an unbelievable creative writer”, according to his mother, Ross. “Anything he does, he does well,” she said.

As a seven-year-old Mr Ross became hooked on the popular computer game SimCity, designing and budgeting his own virtual city. By 10, he had created his own website. He later created his own computer applications and online text games.Soon he was reporting computer software flaws to manufacturers online.

At 14 he was offered an internship at Netscape in Silicon Valley. His mother drove him out to California for three summers in succession.

At Netscape, Mr Ross was introduced to the Mozilla Foundation, a not-for-profit organisation that promotes “choice and innovation on the web”.

Mozilla was already trying to develop an open-source alternative browser to Microsoft’s Explorer, which many analysts felt had grown clumsy and outdated. Mr Ross and his friend David Hyatt began working on a small, user-focused browser. What began as an experimental side-project turned into Firefox.

Mr Ross is quick to point out that he was one of a large team at Mozilla who worked on the project for five years. “It’s a big volunteer effort,” he said. In fact, the pair left before the work was completed, but Mozilla credits them with making the breakthrough. After he left to go to university, Mr Ross continued to be a “significant contributor”, according to Mozilla.

The task involved throwing out all the old codes and rewriting the entire system so it would support all websites on the internet. While Firefox still has a long way to go to rival Microsoft, it seems to be catching on. Firefox has received dazzling reviews from industry analysts. Recently some 10,000 Firefox fans raised $250,000 (£131,000) to take out a two-page advertisement in The New York Times. It is not just in dividual users who are taking interest. In December, the information technology department at Pennsylvania State University sent a note to college deans recommending that the entire 100,000-strong staff, faculty and student body switch to Firefox.

Mr Ross, now a student at Stanford University studying computer science, is taking it all in his stride. As a volunteer on an open-source product, there was no financial reward.

Microsoft professes to be unfazed. Windows executive Gary Schare said: “We’re seeing the natural ebb and flow of a competitive marketplace with new products being introduced. It’s not surprising to see curious early adopters checking them out.”

Not content with making a huge dent in Microsoft’s browser share, Mozilla, the foundation behind Firefox, is also going after Microsoft’s Outlook and other e-mail packages.