1) The instructions on the Open Diameter website for installing on RH9 are quite detailed - have you tried installing it yet, using those instructions? If so, what part are you having problems with?
2) Is there any reason that you are using RH9? This is very old now, and has been unsupported since May 2004. It receives no security updates, so it is a really bad idea to run it on a server. I suggest that you try a more modern version of Linux, such as recent releases of Fedora Core, Centos or Debian.
3) This is a question - not a discussion of an LQ Article. I have reported it to be moved. You have also cross-posted in another forum. Do not do this. Also, LQ is a public forum - never ask for a personal reply by email, you won't get one. This defeats the purpose of a forum.