Hotjava was, as you can see from the UA string in your post, roughly on par with Netscape v3.0 as to its capabilities. It was a project by sun to write a web browser purely in Java. Never went any further if I recall than v3. I think Netscape at some point was seriously tinkering with the notion of writing a browser and mail client purely in Java, but I don't think it went very far at all, if anywhere.
Hey, my 300th post! I'm gonna treat myself to big bowl of hot cream
UserAgent: Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.0.2) Gecko/20030208 Netscape/7.02 (CK-SillyDog)