When Red Hat announced the abrupt end of traditional CentOS in late 2020, the Linux ecosystem was shaken to its core. Developers, sysadmins, and enterprises that relied on CentOS for years suddenly found themselves scrambling for answers. Out of that disruption, two projects, AlmaLinux and Rocky Linux, emerged to carry forward the legacy of CentOS while forging their own identities. This article dives into how these two distributions established themselves as reliable, enterprise-grade options for developers and organizations alike.
The Fall of CentOS: An Industry Shockwave
For over a decade, CentOS was the backbone of countless servers, from small web hosts to enterprise data centers. It provided a stable, free, and RHEL-compatible platform, perfect for developers and administrators building and maintaining critical infrastructure.
That stability came to an end when Red Hat pivoted CentOS to a rolling-release model, CentOS Stream. Instead of offering a downstream, binary-compatible version of RHEL, Stream became a preview of future RHEL updates. This move caused widespread frustration:
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Organizations that built production environments around CentOS suddenly faced shortened support lifecycles.
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Developers who depended on a “set-and-forget” environment now had to deal with the unpredictability of a rolling release.
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Compliance-driven industries were left in limbo, as running on an unsupported OS could trigger security and regulatory risks.
This disruption created a vacuum, and the Linux community quickly stepped up to fill it.
The Birth of AlmaLinux and Rocky Linux
AlmaLinux: Community-Driven, Enterprise-Ready
Shortly after the CentOS announcement, CloudLinux, a company with deep experience in server environments, launched AlmaLinux. The first stable release landed in March 2021. True to its name, “alma” meaning “soul”, the project’s mission was clear: to embody the spirit of CentOS while maintaining community governance. The non-profit AlmaLinux OS Foundation now oversees the project, ensuring it remains free and open for everyone.
Rocky Linux: A Tribute and a Promise
At almost the same time, Gregory Kurtzer, one of the original CentOS founders, unveiled Rocky Linux, named in honor of CentOS co-founder Rocky McGaugh. From the beginning, Rocky positioned itself as a 1:1 binary-compatible rebuild of RHEL, mirroring CentOS’s original mission. Its governance structure, managed by the Rocky Enterprise Software Foundation (RESF), ensures that the project remains rooted in community oversight rather than corporate ownership.
Technical Foundations and Compatibility
Both AlmaLinux and Rocky Linux are built from RHEL source code and aim for near-identical compatibility with their upstream counterpart. Here’s what makes them appealing to developers:
Binary Compatibility
Applications built for RHEL will run seamlessly on either distribution. This includes enterprise workloads like databases, web servers, and container orchestration systems. The file structure, libraries, and core tools are consistent, minimizing migration headaches.
Package Management and Familiar Tools
Both distributions retain familiar tooling:
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dnfandyumfor package management -
systemctlfor service management -
SELinux enabled by default for security
For example, setting up a LAMP stack on either OS feels exactly like CentOS or RHEL:
sudo dnf install epel-release -y sudo dnf install httpd mariadb-server php php-cli -y sudo systemctl enable --now httpd mariadb
This consistency ensures developers don’t have to rewrite scripts or re-engineer automation pipelines.
Long-Term Support
Just like RHEL, both distros commit to 10-year support lifecycles for each major release, which is critical for enterprises that value stability and predictability.
Real-World Use Cases and Adoption
Rapid Community Uptake
When CentOS support ended, organizations needed a drop-in replacement, and they needed it fast. AlmaLinux gained early adopters thanks to its quicker release schedule, while Rocky Linux quickly attracted those who valued its founder’s ties to CentOS.
Enterprise and Scientific Adoption
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CERN and Fermilab, major players in scientific research, standardized on AlmaLinux after extensive testing.
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Cloud providers like AWS, Azure, and Google Cloud now offer official images for both AlmaLinux and Rocky Linux.
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Web hosting platforms and enterprise vendors updated their stacks to officially support these distros.
Developer Ecosystem
For developers, the transition has been smooth. Docker images for both distros are widely available, and CI/CD pipelines that once targeted CentOS can now build against rockylinux:9 or almalinux:9 images without modification.
Distinct Philosophies in Handling Upstream Changes
In 2023, when Red Hat restricted public access to RHEL source code, AlmaLinux and Rocky Linux took slightly different paths:
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AlmaLinux focused on ABI (Application Binary Interface) compatibility, ensuring applications behave identically to RHEL, even if the underlying source code differs.
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Rocky Linux doubled down on exact binary compatibility, forming alliances to secure access to the same source code.
Both approaches keep the promise of a stable, enterprise-grade OS but reflect different philosophies in maintaining compatibility.
Support and Governance
Community and Open Governance
Both distributions are openly governed, with boards composed of community members and industry sponsors. This transparency reassures users that neither project will suddenly shift direction or face the same fate as CentOS.
Enterprise Support Options
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AlmaLinux partners with TuxCare for extended lifecycle support and patching services.
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Rocky Linux offers commercial support through CIQ, catering to enterprises that need guaranteed SLAs and professional assistance.
This hybrid model, community-driven with optional enterprise support, makes both distros viable for a range of users, from hobbyists to Fortune 500 companies.
The Developer’s Perspective
From a developer’s viewpoint, AlmaLinux and Rocky Linux provide everything CentOS once did and more:
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Consistent build environments for applications targeting enterprise servers.
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Stable Docker and container images for cloud-native workflows.
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A predictable upgrade path without breaking compatibility.
For instance, integrating a Rocky Linux base image in a Dockerfile is as straightforward as:
FROM rockylinux:9 RUN dnf install -y python3 git && dnf clean all
This simplicity keeps development pipelines lean and reliable.
Looking Ahead
With CentOS 7 now end-of-life, AlmaLinux and Rocky Linux have become the default choices for RHEL-compatible, community-supported platforms. Their rapid adoption, enterprise backing, and thriving communities signal that they are here to stay.
As the Linux ecosystem evolves, these projects are likely to expand their reach, supporting more platforms, integrating better with modern DevOps tooling, and continuing to ensure that developers and sysadmins have stable, free, and compatible environments for the long haul.
Final Thoughts
The death of CentOS could have left a dangerous void in the enterprise Linux ecosystem. Instead, it sparked innovation and collaboration that birthed two thriving, developer-friendly distributions. AlmaLinux and Rocky Linux not only preserved the CentOS legacy but also improved upon it with stronger governance, broader support, and a renewed focus on community needs.
For developers, the message is clear: whether you choose AlmaLinux or Rocky Linux, you’re building on a foundation that’s stable, reliable, and future-proof.
