If you need enterprise Linux with support, Red Hat wants to sell you Red Hat Enterprise Linux (RHEL). If not, Red Hat will be happy if you use CentOS, the RHEL clone. It's not updated as often, but it does the job. Now, Red Hat is switching things up by offering a rolling release version of its popular server operating system: CentOS Stream.
A rolling release is one in which all of the operating system -- kernel, libraries utilities and applications -- is continuously updated. Examples of these include Arch, Manjaro, and openSUSE Tumbleweed. The more typical roll-up releases consolidate recent updates into a stable tested operating system.
You might well ask why Red Hat would release a version of CentOS, which is the Linux of choice for many hosting companies, data centers, and businesses with in-house Linux experts. The answer, according to Chris Wright, Red Hat's CTO, is it's "a developer-forward distribution that aims to help community members, Red Hat partners and others take full advantage of open source innovation within a more stable and predictable Linux ecosystem. It is a parallel distribution to existing CentOS."
It's needed because the server space is changing faster than ever. With the ever accelerating pace of Linux containers, Kubernetes, microservices, serverless and cloud-native services, companies, which want to stay on the leading edge of technology need a distribution that can keep up with these developments.
That said, Red Hat's community Linux, Fedora, is still Red Hat's bleeding edge release. In the past, changes in Fedora which worked out were slowly incorporated "downstream" into RHEL. Then, RHEL developers hardened and polished these packages added security updates and integrated them into the broader RHEL ecosystem. Only after that would the RHEL source code be released to CentOS.
Now, while Fedora is where the RHEL family starts, CentOS Stream will also play a role in creating the next generation of RHEL. Wright wrote that "developers need something more to address their specific challenges. They require earlier access to code, improved and more transparent collaboration with the broader partner community, and the ability to influence the direction of new RHEL versions. It is these opportunities that CentOS Stream is intended to address."
So, if you need a stable RHEL-like operating system, CentOS will still be there for you. But, if you need to keep up with your competitors who are building new cloud and container-based applications, CentOS Stream will work better for you.
As Wright said, "The CentOS Stream project sits between the Fedora Project and RHEL in the RHEL Development process, providing a "rolling preview" of future RHEL kernels and features. This enables developers to stay one or two steps ahead of what's coming in RHEL."
To be exact, CentOS Stream is an upstream development platform for ecosystem developers. It will be updated several times a day. This is not a production operating system. It's purely a developer's distro. Wright encourages, "users that want to be more tightly involved in driving the future of enterprise Linux, however, to transition to CentOS Stream as the new 'pace-setting' distribution."
Old school CentOS isn't going anywhere. Stream is available in parallel with the existing CentOS builds. In other words, "nothing changes for current users of CentOS."