I'm reporting my positive experience in the installation of Kite on a Kindle 4NT with firmware v4.1.
The goal was to start CoolReader 3.
The approach I chose was to install it using the kite.sh script executed via SSH using the USBNET. The script I used is the one you can download in the first message of this thread.
Launching the script as it was did not work, so I looked for what was wrong:
In Kindle4 the system startup is not made with the normal linux runlevels, so the directories "/etc/rc5.d" and "/etc/rc3.d" do not exist and are replaced by "/etc/rcS.d" that is equivalent to the "/etc/rc5.d".
So, the command "ln -sf ../init.d/kite /etc/rc5.d/S62kite" must be replaced by
"ln -sf ../init.d/kite /etc/rcS.d/S62kite",
the line "ln -sf ../init.d/kite /etc/rc3.d/K07kite" has to be removed and as consequence the following line of the kite-uninstall.sh file "rm -f /sbin/kite /etc/init.d/kite /etc/rc5.d/S62kite /etc/rc3.d/K07kite" becomes "rm -f /sbin/kite /etc/init.d/kite /etc/rcS.d/S62kite"
I did not test the installation with a new script but I first manually extracted the files (the kite shell script, the kite executable) then I copied them to the proper destination locations (/etc/init.d, /sbin) and executed the diffrerent "mntroot", "chmod and "ln"
After this everything worked and I could use CoolReader 3!