Mozilla was more of the continuation of Netscape back in the early days. It seems to me that it has been a browser choice of open source software demanded invidivials. Over time, it's tinted with strong extremist feeling.
Google Chrome is also open source, but it does not enjoy the same love as Mozilla from open source community. I guess it's because Apple has not been loved by the said community. (e.g. Don hates anything associated with Apple.) It's very religious to me.
I have both Firefox and Camino installed so I can have two different sets of bookmarks.
UserAgent: Mozilla/5.0 (iPhone; U; CPU iPhone OS 4_3_5 like Mac OS X; en-us) AppleWebKit/533.17.9 (KHTML, like Gecko) Version/5.0.2 Mobile/8L1 Safari/6533.18.5