That citrix client won't work in anything but OS2005.
Flashing back that far is pretty bad, and you will still have to use an external keyboard with the citrix client.
I used citrix with OS2005, it did work.
The citrix app for Windows Mobile on something like a Axim is alot easier to deal with, the virtual keyboard works on that one.

True Java applets are still waiting for a real Java VM, not quite here yet.
Javascript is not the same as Java.