Why does redhat seem to be so popular in the enterprise world? [closed]

Title says it all. For personal usage, I tend to prefer Debian/Ubuntu over Redhat. It's not necessarily that I dislike Redhat (or more specifically CentOS or Fedora) so much as it is that I like Debian's package management system so much better.

What are the reasons why Redhat is so popular?

(And just to be clear, I'm asking because I genuinely want to know what the reasons are. So no flame wars!)

In the early days of Linux being taken more seriously in the everyday business world there was always a nervousness that followed mention of the name. Tech employees found that "It was started by a university student in his basement" wasn't the best way to sell the idea of an Open Source operating platform to management.

The need for a solid company backing Linux alternatives was filled by Red Hat in those early days and probably had the single biggest impact on Linux for the Corporate Masses. They were able to provide support solutions along with their own branded versions of the OS.

Thanks to their early success with the full range of Linux uses from personal to corporate, they built up a huge amount of momentum and a recognisable brand which remains with them to this day, even with competition from other big names like Novell.

If you are living in an enterprise IT environment you often find yourself in what I call the 3rd-party-vendor-support-matrix-hell. Meaning for every decision you make you have to make sure that whatever OS/software/hardware you are using is "supported" or "certified".

RedHat Enterprise Linux is simply found on almost every support matrix from commercial software and hardware vendors. You might also find Novell/SuSE SLES on the matrix. But then that's it. End of supported Linux distributions. And even then these vendors often only list RHEL releases which are at least one generation behind the current major release. That's where the long term support offers from RedHat become important.

It is also very important to many managers that there is a company you can point your fingers at and open support tickets in case of problems.

We use it because it's one of the few flavours of Linux that Oracle will (officially) run on.

My company went with Redhat 7.3 when we migrated off of solaris in 2001/2002. At the time, they had the best support for the hardware we were using (Dell, which we chose because we already had a vendor contract with them from our Windows systems).

When we reached the next decision point, I heavily considered Debian (Ubuntu, which is desktop focused, was not around and would not have been considered if it was). The problem was,at the time it had been something like 2 years since the last stable release and it was horribly out of date. Everyone was using the testing trees for production and it felt nasty. We ended up choosing Red Hat Enterprise Linux, followed shortly by using CentOS when possible and only using RHEL when we had a support contract issue with another vendor (cough oracle cough) that required a true-blue RHEL install with a support contract.

The big upside for us was the support life cycle - if I install RHEL on a server, I know I'm going to get 5 years of support life cycle, including security bug fixes. That life cycle gives us warm fuzzies when maintaining the servers.