If you're not familiar with the Red Hat Linux world, you might ask why you should bother at all looking at this enterprisy Linux. After all Ubuntu is for sure the most successful desktop Linux distribution which even has 'long-term' support (LTS releases). Alternatively Debian might be seen as a stable distribution without too much commercial influence.

Well, Red Hat enterprise Linux beats these alternatives single handed in my use cases:

7 years of security support for every major version (4.x, 5.x, 6.x) for all packages
This is already a significant advantange over Ubuntu's LTS for me because Ubuntu's LTS does not really have "long-term" support:

• Packages from the universe/multiverse repositories don't have any long-term support, sometimes they are more like some quickly created packages without a community of packagers maintaining them.
• desktop packages are only supported for three years, afterwards you're left alone.
• And last but not least it's only 5 years support even for server packages.

I run a couple of Linux servers and even today (July 2011) I'm running 3-4 CentOS 4 boxes. CentOS 4 was released initially in 2005 and these servers now run for more than six years now without problems.

Unlike Debian installs I did not have to upgrade my install (with the need to adapt configurations because of new major versions being incompatible with the previously installed versions). All I had to do is to install updates coming in though yum.

Red Hat invests a significant amount of time to update all the old components (RHEL 4 comes with Linux kernel 2.6.9) in order to minimize disruptions. Which means I can plan very well when I do a major upgrade of my servers. Currently I'm planning to retire to the old CentOS 4 boxes but I had more than two years for the actual migration which really helps!

Fedora as a Technology Preview
At the same time I can run Fedora on my desktop or on servers which really need the "lastest and greatest" technology. As RHEL is based on (older) Fedora releases the administration is very much the same. I can create private RPM packages for Fedora and reuse them with minimal effort on RHEL/CentOS.

Fedora EPEL provides all other packages
​Fedora EPEL is a Fedora subproject which provides more high-quality RPM packages for RHEL/CentOS in a transparent, reliable way. It is based on Fedora's standards, policies, and technologies so there are a lot of good packages which are even updated constantly. Usually it's quite easy to jump in and fix things and with co-maintainers it's not so much of a problem if an individual packager has no time anymore to update packages.

The high quality of these packages is also demonstrated by the fact that Red Hat often blesses EPEL packages as 'official' and distributes them as part of RHEL.

Red Hat/Fedora really take packaging seriously
It's a small point but comes in handy more often than most people think:

• Each RPM has a changelog section where each packaging change is listed.
• Usually packages have only the absolutely required dependencies with subpackages for specialized functionality which requires additional packages. On the other hand I found Debian sometimes to be too granular which makes it hard just installing some meaningful functionality.
• Package installation/updating can be done completely unattended. Fedora's packaging policy mandates that there is no user interaction. This might be bad for a "Desktop installer"-style installation with initial configuration but it ensures that you can set up systems completely unattended.
• Services are not restarted automatically after updates. I was burned once on Suse Enterprise Linux 9 when I just updated some packages while waited for all user to log of so I could start the actual maintenance. Unfortunately several services were restarted automatically which caused TCP connections to reset which in turn caused data loss for some users.

Red Hat and Fedora take Free Software and community seriously
There is very little "secret sauce", most of the stuff is done in the open. I don't remember Red Hat dictating big changes, new features is introduced through Fedora and people with enough merits can influence these decisions. Most (all?) software from Red Hat is released under a free software license.

Also Red Hat provides source RPMs publicly and does not make any attempts to prevent free "clones" like CentOS and Scientific Linux: ​merging all kernel patches into one big patch is ​not a GPL violation and does not affect the community clones but rather Oracle as a commercial free-rider.

So that's why ​Red Hat earns more money every year even if they 'just' publish a Linux distribution.