You know what's weird. I just realized I've been using Firefox for almost 6 years now. Outside of Operating Systems, utilities like bash or ls (that kind of stuff), or "server software" like Apache; I believe this is the longest stretch I have ever used a piece of software. (Disregarding a brief period in which I was using Camino.) At least, I can't think of any piece of software I've used longer (end-user type software, like I said, not counting stuff like Debian or the perl interpreter).
I'll list software here that, as I recognize it, I have used longer than Firefox.
- NEdit — my editor of choice when I am on *nix computers that do not come with TextMate.
- EditPlus — not sure if I used it for 6+ years, but it was my editor of choice on Windows for a long time.
- vi/vim — I only use these if I cannot realistically get an X session, but I guess if I am listing editors separate from utilities like
bash, I've used vi/vim longer than 6 years… certainly.
- Eudora — I used that as my email client from 1996-1997-ish until I switched to Thunderbird around it's 0.3 release, which appears to have been around October/November of 2003.