Which is newer and what's the difference? If RHEL3 is newer, can 9 be upgraded, or does it require a wipe and fresh install? I just happened to come across an unopened disk set of RHEL3.

RedHat 9 was the last non-commercial RedHat release. After that the non-commercial stuff is called Fedora and the commercial stuff is called RH EL. RH EL 3/Fedora Core 3 are the 3rd major releases AFTER RH 9.

I don't know if there was an upgrade path. From my experience in Unix I always simply reinstall when I want to change the major release. Upgrading even if possible and done with a lot of planning always seems to still leave you troubleshooting something you've missed. Also it leaves behind a lot of stuff that is no longer relevant but you're afraid to delete as you're not sure what is and isn't.

For package and minor update changes I'll do those as there is usually a method. For RH EL it is up2date and for Fedora it is yum. Unless you're paying RH for a RH EL up2date subscription I'd recommend going to Fedora Core so you can use yum. FYI: Even RH EL /Fedora Core 3 are a few years old. There are now release 5's for both. I'd recommend going to at least release 4 so you can get the 2.6 kernel.

To my knowledge, RedHat was the "original name" of the distribution. The last number was RH9, and after that the thing got divided in sort of a way, the free version became Fedora Core (nowadays version 5 stable) and the commercial one RHEL, RedHat Enterprise Linux. So, RHEL is newer. Actually they take a Fedora Core release (which is like a playground for RHEL) and create a RHEL release out of it - that's why Fedora Core versions are always one ahead (RHEL3 ~ Fedora Core 4 etc.)

I'm not sure if RH9 can be upgraded that easily, I'd suggest clean install of RHEL. The enterprise version has newer software, updates and patches, but RH9 is not "dead meat" anyway..if you're okay with it, do a clean install of the enterprise version (if you can pay for it; for free you can get the Fedora Core, but it's not that stable...)

OK, I have the full version that came with a Dell server, but was never used, the package was still sealed. I am using a demo server to test out Rancid, and just waiting to find out which files I should move to the FTP server before rebuilding the server. Final question, is there anything in RHEL that isnt in Fedora that I will need? I plan to use CVS, Apache, Expect, Perl, MySQL, Named(BIND), Radius, TFTP, FTP, and a few others that are currently on the RH9 version. Can I also downgrade Apache and MySQL to earlier versions on Fedora or RHEL3 to 3.53x for MySQL, and I dont remember the apache version I am running on the other server, I think apache 5 is running on the demo one. The Demo one I can run whatever I want, even OpenBSD if I want, but I need to test out the OS with certain version of MySQL and Apache due to some software restrictions from other inhouse servers(compatability issues).

Fedora is the testing ground for RH EL. Therefore Fedora usually has things that haven't necessarily made it into RH EL yet. Since RH EL is intended for commercial (including support by RH) purposes what it includes is going to be more conservative than what Fedora does. The only difference I'm sure of is up2date for RH EL vs yum for Fedora.

You can actually run the RH EL - You would just then have to figure out how to do yum updates to it or worse yet install individual rpms and sort out dependencies for yourself. (The beauty of yum and up2date is they'll bring in dependencies automatically.)

As to running earlier packages. So long as you have the original rpms you probably can (with the dependencies caveat noted above) but why would you want to run something other than current versions?