You may be interested in this article:
http://www.groklaw.net/article.php?story=20050123185736414

The top few paragraphs are about the design philosphy of Firefox. It's beautiful. I'll quote my favourite part, this is the original Firefox developer speaking:

"I remember sitting on IRC with Dave, Ben and Asa painstakingly debating feature after feature, button after button, pixel after pixel, always trying to answer the same basic question: does this help mom use the web? If the answer was no, the next question was: does this help mom's teenage son use the web? If the answer was still no, the feature was either excised entirely or (occasionally) relegated to config file access only. Otherwise, it was often moved into an isolated realm that was outside of mom's reach but not her son's, like the preferences window."

Last Updated 9 June 2006