What are alternative browsers for OS 10.3.9? Where find download/install files? Too many major websites are using features that in-effect are "walking away from" my old OS 10.3.9 and Firefox 2. (That is, my favorite browser, and its available plugins and extensions, are starting to no longer render some common websites properly, or at all.)  I would like to experiment with alternative browsers but do not know which ones have archived "antique" versions that can be downloaded and installed on such an old Mac.  Any advice (apart from "Upgrade to 10.4...")?  My machine is a PowerPC "iMac" -- the version with the white half-sphere base and the moderately thick flat-screen on a "stalk" -- sort of like the movie "Wall-E" but with a rounded body.
"Upgrade" is going to be the standard answer. Your computer is over 10 years old now, has a slower processor and less memory than my phone, and is well into the timeframe where it can be expected to stop working without notice. If you still have the original disk drive, it is now at twice it's expected service life. But of course you have a backup.

Most software vendors do have old-version archives, but you have to dig for them. Most websites do not maintain compatible versions - mine certainly do not, I cut off at IE9 and I do not test older versions of Chrome, Firefox etc. I'm a bit surprised this site runs on Firefox 2.

You can get a brand-new Air or iMac for $1000. For twice that you can put a 27 inch model on your desk, either one running the latest of everything. And you're good for another decade.