I tried IE 5 on my dual-core Power Mac G5 running Leopard last summer. If anyone gets the sudden urge to browse the web like it's 2001 on a Mac from 2005 running an OS from 2007, yes it can be done.
Oh, and I recommend you go to the Internet Archive and pull up webpages that are more... friendly.
Because it's fun to do things just because you can do them!!!!!! Sorry for yelling. Oh, and I had fun also getting an older Office 98 disk and even though I couldn't install it, I was able to copy the fonts and clipart to my machine! Talk about an exciting Sunday night!