The servlet.jar in Kaffe will not work. It is only a shell.
There is another LGPL implementation that was written by Paul and Mark
Wielaard. It is available at http://www.euronet.nl/~pauls/java/servlet
these will have (have been?) added Apache JServ package so the user doesn't
have to download Sun's classes any longer.
6.3 Do I need non-free Java in order to run servlets?