I started using Mozilla and Opera browsers around 2001, when I started experimenting with Linux as a secondary workstation at work, to learn more about this environment.  I started with the full Mozilla suite, which included email client capabilities.  Later in 2002, I discovered the Windows beta versions of Mozilla, including Phoenix 0.3 browser (which was installable only in a zip build configuration). Later Firefox, Thunderbird, Seamonkey, and other products emerged from developers. 

The competition between Firefox and Internet Explorer has led to improvements in functionality and security for both browsers.  Below are links related to Netscape's creation of the Mozilla initiative, which later led to Mozilla becoming the leading open-source technology for web browsers. Personally, I like IE 7, Firefox 3, and Opera 9.  Hopefully, innovation and protection  will continue for all these products in the future. 

Happy Birthday Mozilla!
http://isc.sans.org/diary.html?storyid=3875

QUOTE: Let's just all thank Mozilla for the wonderful browser and market they have created.  I've always said diversity is key.  It's great that I have been to hundreds of organizations and I can honestly say that each one has had Firefox installed.  Maybe not the default browser, but at least had it installed.

January 22, 1998 -- the Beginning of Mozilla
http://weblogs.mozillazine.org/mitchell/archives/2008/01/january_22_1998_the_beginning.html

NETSCAPE ANNOUNCES PLANS TO MAKE NEXT-GENERATION COMMUNICATOR SOURCE CODE AVAILABLE FREE ON THE NET

QUOTE:  MOUNTAIN VIEW, Calif. (January 22, 1998) -- Netscape Communications Corporation (NASDAQ: NSCP) today announced bold plans to make the source code for the next generation of its highly popular Netscape Communicator client software available for free licensing on the Internet. The company plans to post the source code beginning with the first Netscape Communicator 5.0 developer release, expected by the end of the first quarter of 1998. This aggressive move will enable Netscape to harness the creative power of thousands of programmers on the Internet by incorporating their best enhancements into future versions of Netscape's software. This strategy is designed to accelerate development and free distribution by Netscape of future high-quality versions of Netscape Communicator to business customers and individuals, further seeding the market for Netscape's enterprise solutions and Netcenter business.