I have about the same time in Linux as you but how I found out about SL was due to the delays CentOS has been having. Previously, the CentOS releases were not far behind RHEL releases as far as timing. But when 6.0 failed to show up I visited the CentOS forum.

For whatever reason that only the internal developers know, announced milestone after milestone were delayed. The chief complaint about CentOS has been the lack of openness or transparency with the devs. Numerous offers to help and contribute to the project have not been accepted. With little feedback or request for help, users became antsy if the CentOS project was dead in the water. That's where Scientific Linux seemed to have found some new users when they were the first out of the gate with a version 6 based on RHEL.

While it's great that CentOS 6.0 is out, maybe the better question is to ask why not 6.1 which was already released by RHEL some time ago (May 19th) that addresses some security issues.

I used CentOS quite a bit but have moved off to distributions as I'm happy to pay for some software and contribute to other ecosystems where there is an openness to them.

> The "why" is that CentOS has brand recognition

The real brand is RHEL. Otherwise people don't care much what the brand of the binary compiled Linux they are using. We switched from CentOS to SL to CentOS.

To be honest, the staff @ CERN and Fermilab inspire more confidence in their commitment to their distro than the CentOS. I understand the guys have full time jobs and do this on the side, but in the end that becomes kind of irrelevant for some new end user who is just looking for binary compatibility with RHEL.

> This is the first time I've heard that "Scientific Linux"

Then you haven't followed the linux distros (especially RHEL binary compatible clones) close enough. SL is actually older than CentOS.

Re: Haven't followed the linux distros close enough.

Yes, that is my point. I'm not challenging the fact that SL is a credible, (possibly much more so) alternative to RHEL than CentOS - I'm just trying to point out that if _I_ didn't know that SL was a goto distribution for people who needed a rebuild of RHEL, then I'm fairly certain 95% of the IT population doesn't either - and that's why _they_ go to CentOS - it's a name they know and trust (for better or worse)

BTW - in my defense, I just hopped onto my SliceHost/Linode Dashboard, and, of the 56 version/distros they offer, Scientific Linux is nowhere to be found.

But now that you know about it do you care really what it is called, if it is just a binary compatible RHEL distro. If CentOS disappeared tomorrow you could just run your software on SL, or buy a RHEL license. I certainly do not want to trivialize the work that CentOS and SL do (and it is a lot of work to maintain these distros) but when the main point of the distro is to be a binary clone of another distro, brand names become meaningless. We could switch from SL to CentOS and then go back. It wouldn't be that hard. If another clone appeared tomorrow we could switch to that. The only criteria is reliability of release and promptness.

The "Brand" CentOS says to me "This distribution is binary identical to RHEL - you can do all your development on it, and deploy hundreds of servers running it - and be able to run all of the software qualified for RHEL. You can also write, and test, software on this platform, and have your _customers_ then run that software on their instances of RHEL"

I don't have that level of faith in SL's distro, it will probably take a year or so of observation before I would consider it a potential replacement for CentOS.

Even convincing engineers, and developers, that they could develop on CentOS and have some assurance that their code would run fine on RHEL without extensive regression testing was a challenge.

And even with all this - Oracle won't provide you support if you run their RHEL qualified Database Server on CentOS.

I guess this is just a long way of saying, I _don't_ know that SL is a binary compatible RHEL distro, but I do know that about CentOS. That's what the brand name does for me.

Hardly anyone will provide you with support for commercial products under Centos. You just have a reasonable confidence.

Here's another data point. I've been using Red Hat since 6.0 (and later RHEL and Fedora). I have used CentOS in the past. This is the first time ever I've heard about Scientific Linux. Also, none of the VPS services I use support it. They all support CentOS.

What I'm saying is that it's really not a a "mainstream" distro.

> This is the first time I've heard that "Scientific Linux"

"Then you haven't followed the linux distros (especially RHEL binary compatible clones) close enough. SL is actually older than CentOS."

I was trying to explain that your average Linux sysadmin is aware of RHEL and Centos, but not "Scientific Linux". That's all. I stand by that statement.

I've been building, running and configuring Debian, Fedora, Centos and RHEL systems for over a decade and I've never even heared of "Scientific Linux"

very sad...

Why this?

Probably because your comment added nothing. FWIW, I hadn't heard of SL either, despite having used and administered Linux distributions for the past 15 years. Feel free to use that fact to call my entire career into question, too, though.