In fact, I've used it on a 486-33 under Windows 3.11. You will need a separate mail client such as Juno or Outlook Express. You will also need to download Sun Java 1.2.2 if you want Java capability. It does support JavaScript. It is also designed with the handicapped in mind.
Opera is trialware.
You have 30 USER days to test it. Although it must be purchased, OperaSoft has a very liberal upgrade policy. It's worth a free preview. NET FOR KIDS is a great browser for children. It works like mom and dad's browser, but its just for the kids.