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Ever since I installed Linux back in 2003 I've been a keen advocate of free, open source software. Lacking marketing power but strong on design, open source software was never going to suddenly destroy its proprietary competitors. Nevertheless, the steady growth of Firefox since its launch in November 2004 shows just how powerful such software can become in the minds of users.
Firefox is the "killer app" that introduces people to the concept of open source software. The more people that use Firefox, the more understanding there will be about the usefulness and importance of open source software. And the result of this will be a greater usage of such software.
The ultimate goal for people like myself is the growth of Linux as an operating system. When I first installed it back in 2003 it was clear even then that it was not mature enough. Yet my experience running Kubuntu in the last 12 months shows that changes have been made.
Firefox is essentially a gateway into open source software. After Firefox, people probably start thinking about Thunderbird as an email option. After that, OpenOffice competes with Microsoft Office, The Gimp competes with Photoshop and .ogg competes with .mp3.
Perhaps the best known example of the theory behind open source software is Wikipedia. The software itself (a Wiki) is open source, but the explosive growth, importance and influence of Wikipedia has shown just how much the world can be influenced by open source.
Wikipedia is already the 11th most visited site on the internet. Back in February 2004 (when I first started contributing) it was the 874th most visited site. Wikipedia's explosive growth is essentially due to its easy acceptance by people on the internet. Open source software will never match Wikipedia's growth rate, but it will, eventually, dominate the computing world. Not now, probably not in five years, but the further into the future you go the more dominant open source will become.