non-backwards compatible versions of ubuntu

[Michael J. White]

For the most part, I  just read the messages and try to learn.  I am a 
user, not a developer.  I do have a question that I think should be 
directed to developers, however.

I create and use a lot of PDF files.  I am not aware of any program to 
edit PDFs which works well under linux, Ubuntu or otherwise.  But kpdf 
is the best program I have found for printing them.  I have used 
document viewer, xpdf, and zpdf, and I find them all unsatisfying.  
Under Ubuntu 8.04 (running on two of my machines) and on my Debian 
machine, I can get kpdf ... but not under Ubuntu 9.04.  I have tried 
both add/remove software and the synaptic package manager. 

I just added kpdf to a machine running 8.04, so I know it's still out there?

Why is this functionality disabled under the latest version of Ubuntu?   
How can I still get it?

Michael