There is no CentOS 8, there is only Stream

When IBM bought Red Hat in 2018 (who of course maintains Red Hat Enterprise Linux as a paid product and Fedora as its free community upstream, and since 2014 the de facto free version of RHEL, CentOS), as a Fedora user since it first booted on the Talos II, I had high hopes that finally OpenPOWER would be a first-class citizen on par with x86_64 under IBM's hopefully gentle goading. No more of this being in the alternative architectures penalty box for Fedora Workstation, for example. The idea was that IBM would see Red Hat's free open products as a logical extension of OpenPOWER and exploit the obvious synergy by having a free distribution available as a preferred choice on an open platform (and then the customers who want greater support and enterprise features could pony up). Win-win, right?

Well, first-class OpenPOWER Fedora still hasn't happened, and while RHEL remains perfectly happy to take your POWER8/POWER9 money, CentOS — or at least CentOS the way you've understood it, i.e., RHEL without the price or support contracts — is dead. There is no CentOS, there is only Stream (after 2021, that is, though CentOS 7 will finish its lifecycle as usual).

Let's be a little less handwringy, though, as Red Hat could have done a better job explaining what this means. As I so presciently determined back in 2019, Stream was clearly positioned as the "public beta" for RHEL and, at that time, for CentOS. It still is; this "merely" means there will be no stable channel. I also presciently determined in that 2019 article that there would be a relatively small slice of people who want "just enough" innovation compared to us on the bloody (Fedora) or bleeding (Rawhide) edge, but still prefer somewhat more current updates than those on regular RHEL or CentOS. Unexpectedly, Red Hat appears to have solved this problem by just eliminating classic CentOS. But people willingly pay good money for RHEL — or, you know, use CentOS — because stuff doesn't break much. Stream eliminates that "doesn't break" guarantee, as much as a free distribution could make such a guarantee in the first place, though it's definitely much less churn than Fedora and for many users will still fill the bill. Unlike Fedora, on CentOS Stream 8 you won't be forced to dogfood Stream 9 any earlier than an RHEL 8 user would be, though you may be forced to deal with 8.x.

There are certainly other RHEL downstreams because there must be (it must be open: that's how CentOS started in the first place). Amusingly, some of these are other proprietary vendor Linuces (Oracle Linux, Hewlett-Packard Enterprise ClearOS, etc.). But, and now getting to the OpenPOWER specific portion of this article, none of the free (as in beer) options run on POWER8 or POWER9. Springdale Linux, one of the few free rebuilds, is strictly x86, and Oracle Linux is free to download but only supported on aarch64 and x86_64 (sorry, SPARC). ClearOS is free but stuck on RHEL 7 and doesn't run on OpenPOWER either, and while CloudLinux claims to run on anything RHEL does, it costs money, so you might as well run RHEL unless you need its specific value-added features. [UPDATE: CloudLinux is now announcing a free community version in Q1 2021. No word on OpenPOWER support, but we're hopeful. Thanks Dimitris Z for reporting it.]

That leaves the recently announced Rocky Linux, led by Gregory Kurtzer, founder of the CentOS project. Rocky Linux aims to basically be what CentOS was originally: a downstream build of RHEL, without the branding or the fees. But all it is right now is an idea and no downloads are available, nor any indication that OpenPOWER will be supported, at least not as of this writing. When they come to a decision on that you'll hear it here first.

On the whole this announcement is probably of little concern for people using their OpenPOWER machines as workstations, because most of those that run a Red Hat derivative are probably running Fedora (yours truly included). A few will be running CentOS Stream, but that isn't going anywhere. Where this hurts is those individuals who wanted the superstability of CentOS without the supercost of RHEL, and that probably applies to a substantial number of people running OpenPOWER servers in high-availability environments. Many of these people will still be reasonably well served by Stream, but a few are so risk-averse that even Stream's small amount of turnover won't do for them either. That's no skin off IBM's nose because they'd rather have them as customers paying support fees, but it's not a good look for free computing, and it's not a good look for Red Hat specifically.

Which brings me to another prediction I made: "our worry is that the IBM monolith will affect Red Hat far more than the other way around." Is it my curse to always be right?