Java Applet vs. AJAX for continuous data

I just saw a Java applet that establishes a continuous
connection with the server to display data like a chart
recorder -- very cool. I did some searching to see how
this differed from an AJAX technique along with the pros
and cons, but so far I have yet to get much insight.
I'm interested in performance (fastest that each can
reliably update the browser), reliability, security, and
customization (looks like a Java applet can be made to
look like a chart recorder with controls), etc. So, I
hope someone that has done both can comment on the
differences, pros, and cons of each. I'm using JavaScript
and doing an AJAX application that does a similar thing,
but I have not ventured into Java and applets yet (on the
To Do list when I have time). Thanks for the help.

Yes, I know this is a JS NG, not a Java NG, but I can hope,
right? Besides, this web interface doesn't seem to allow
cross posting, so...

Dave Boland
---
d boland 9 (all 1 word) at Fastmail period fm

.