Macintosh browser for OS 9

We came across an issue today, in that our web-based email software requires at least Internet Explorer 5.5. The problem is that one of our clients is strictly a Mac-based company, running OS9. The deeper problem is that the newest IE they can use is 5.1.something. Safari requires OSX, as does Firefox. What other options do we have?

Camino, Opera, Firebird, I believe are all options. They are also all mozilla builds.

Thanks Paul, I'll give those a try.

Lollerskates at people still using OS9. GET WITH THE NOW!!!

They don't want to use OSX, because they are afraid that their old software won't work (I know, I tried to tell them about Classic Mode, but they have a different company that takes care of their Mac-specific issues that told them not to upgrade (THEY EVEN HAVE NEW G5's RUNNING OS9, HOW STUPID IS THAT!!??)).

G5's don't even run OS9 unless they hacked them. If your software is holding you back on something as important as moving from OS9 to OSX, it's time to get new software.

Gotcha. I did a Google image search, they have the G4, not the G5:
http://www4.macnn.com/appleinsider/articles/9908/images/g4-mockup.jpg

....see, shows how much I know about Macs.