Why AlmaLinux, Rocky Linux, and Other RHEL Clones Exist
Introduction
If you’ve heard about Linux, you probably know it’s a computer operating system, like Windows or macOS. What makes Linux special is that it comes in many different versions, called “distributions” or “distros.” Imagine a car company that lets anyone use its basic car design to build their own custom vehicles. That’s similar to how Linux works.
In the business world, one of the most important Linux designs is called Red Hat Enterprise Linux (RHEL). It’s known for being extremely stable, secure, and well-supported, which is why it powers critical systems in banks, governments, and large corporations. In fact, a recent report suggested that 90% of Fortune 500 companies use RHEL .
But what if you want the reliability of RHEL without the cost? This is where distributions like AlmaLinux, Rocky Linux, and others come into the picture. They are built to be compatible with RHEL, offering a similar experience without the price tag. This article will explain why there are so many of these RHEL-based distros, why we need them, and who uses them—all in simple, easy-to-understand English.
The CentOS Shock: The Birth of a New Era
To understand why AlmaLinux and Rocky Linux exist, we first need to talk about a distribution called CentOS.
For years, CentOS was the free, community-built version of RHEL. While Red Hat charged for support and certification, CentOS offered a nearly identical operating system for free. It became incredibly popular, especially among startups, universities, and developers who needed enterprise-grade stability without the enterprise-grade price.
Then, in December 2020, Red Hat dropped a bombshell: it would be discontinuing the traditional CentOS and shifting its focus to a different model called CentOS Stream . For many in the community, this was a major problem. CentOS Stream is more of a testing ground, positioned just ahead of RHEL in the development cycle. This meant it wouldn’t have the same “rock-solid” stability that users had come to depend on for their critical systems.
This created a huge void in the Linux world. The community needed a free, stable, and binary-compatible alternative to RHEL. This need sparked the creation of two major new projects almost overnight.
- Rocky Linux: Announced just hours after the CentOS news, Rocky Linux was started by Gregory Kurtzer, one of the original co-founders of the CentOS project . He named it in tribute to another CentOS co-founder, Rocky McGaugh . The goal was to continue the original mission of CentOS: to be a “100% bug-for-bug compatible” clone of RHEL .
- AlmaLinux: Almost simultaneously, another distro emerged. AlmaLinux was created by the company CloudLinux, which already had experience building a stable Linux OS for web hosting providers . The name “Alma” is inspired by the Latin word for “soul,” “kind,” and “nourishing”. AlmaLinux was also designed to be a community-owned and governed replacement for CentOS .
A Crowded Family: Meet the RHEL-Based Distributions
While Rocky and AlmaLinux are the most prominent new players, the family of RHEL-based distributions is quite large. Here are some of the key members:
| Distribution | Key Sponsor/Backer | Primary Focus & Notes |
|---|---|---|
| Red Hat Enterprise Linux (RHEL) | Red Hat / IBM | The original commercial product. Focuses on stability, security, and paid support. |
| CentOS Stream | Red Hat | The “rolling preview” of RHEL, used for testing future features. |
| AlmaLinux | CloudLinux / AlmaLinux OS Foundation | A free, 1:1 binary-compatible RHEL replacement with strong corporate backing. |
| Rocky Linux | CIQ / Rocky Enterprise Software Foundation | Aims to be 100% bug-for-bug compatible with RHEL, with a strong community focus. |
| Oracle Linux | Oracle | Fully compatible with RHEL, but optimized and supported for Oracle’s hardware and software. |
| Scientific Linux | Fermilab | Created by scientific laboratories for use in research environments. (Now discontinued) |
| Amazon Linux | Amazon Web Services (AWS) | Optimized for running on Amazon’s cloud infrastructure. |
Other notable distributions in this family include ClearOS for small businesses and home users, and newer entrants from Asia, such as OpenCloudOS from China.
Why So Many? The Reasons Behind the Explosion
You might be wondering, “If they all do basically the same thing, why are there so many of them?” The reasons are varied and reveal a lot about how the open-source world operates.
1. Different Philosophies and Goals
Even though the base is the same, each project has a slightly different vision.
- Rocky Linux’s philosophy is deeply rooted in the original CentOS spirit. Its goal is absolute, 100% compatibility, driven purely by community needs .
- AlmaLinux, while also compatible, has shifted its stated goal from being a “1:1 binary compatible” clone to being “RHEL binary compatible,” which gives it more flexibility . It is backed by a non-profit foundation, ensuring it remains free and open .
2. Corporate Backing and Commercial Interests
Some distributions exist to support a company’s larger business strategy.
- Oracle Linux ensures that Oracle’s expensive database software runs perfectly on its own platform.
- Amazon Linux is tuned specifically for AWS, making it the best-performing and most secure option for customers running workloads on Amazon’s cloud.
- The backing from CloudLinux for AlmaLinux and CIQ for Rocky Linux provides financial stability and dedicated developers, which helps these projects release updates quickly and reliably .
3. Handling Red Hat’s Source Code Changes
In 2023, the situation became more complicated. Red Hat announced it would no longer make the complete, easy-to-access source code for RHEL publicly available . This was a big challenge for the clone distributions that depend on that code.
How they responded highlights their different approaches:
- Rocky Linux decided to stay the course. They found other ways to get the RHEL source code, for example, by using pay-per-use cloud instances that have legitimate access to it. Their goal of being “100% bug-for-bug compatible” remains unchanged .
- AlmaLinux adapted. They now use “several sources” for their code and focus on ensuring their system can run any application built for RHEL, even if the underlying package isn’t an exact clone .
This event showed that while the distros are similar, they can adapt differently to survive in a changing environment.
The Big Question: Why Do We Need These Distributions?
With RHEL itself being so successful, it’s fair to ask why these free alternatives are necessary. Their existence is crucial for several reasons.
1. Freedom and Choice (No Vendor Lock-in)
“Vendor lock-in” is a scary term for businesses. It means you become so dependent on one company’s products that switching away becomes difficult and expensive. The presence of multiple RHEL-compatible distros ensures that no single entity has absolute control over this critical piece of technology. If one distribution changes its policies in a way the community doesn’t like—as happened with CentOS—users have other places to go .
2. Cost Savings for Everyone
Not every organization can afford a RHEL subscription. Startups, students, non-profits, and researchers can use AlmaLinux or Rocky Linux to learn, build, and even run their businesses on a enterprise-grade operating system for free . This fosters innovation and makes powerful technology accessible to a much wider audience.
3. Stability and Long-Term Support
Enterprise operating systems aren’t like phone apps that get new features every few weeks. Businesses need stability. A web server running a company’s online store needs to work reliably for years. RHEL and its clones offer very long support cycles—up to 10 years . This “set it and forget it” stability is essential for business infrastructure.
4. A Thriving Ecosystem for Developers and Admins
For system administrators and developers, knowing how to manage a RHEL-style system is a valuable skill. The widespread availability of free distros like AlmaLinux and Rocky Linux allows anyone to:
- Learn and practice their skills at home or in a lab.
- Develop and test applications on the same type of system that will run in their company’s production data center.
- Ensure their software is compatible with the broader RHEL ecosystem.
5. Specialization for Specific Needs
As we saw with Amazon Linux and Oracle Linux, sometimes a one-size-fits-all solution isn’t perfect. Different environments have different needs. The ability to create a specialized distribution—whether for the cloud, for scientific computing, or for security—allows for optimization that benefits everyone.
Who Uses These Distributions?
The user base for these operating systems is vast and varied. You’ll find them in almost every industry.
1. Large Corporations
While big companies might pay for RHEL support for their most critical systems, they often use the free clones for development, testing, or internal tools. Furthermore, companies like Toyota, Samsung, and the Cigna Group are all listed as users of RHEL for application development, indicating the type of large enterprises that rely on this ecosystem .
2. The Web Hosting and Cloud Industry
This is one of the biggest users of distributions like AlmaLinux and Rocky Linux. Web hosting companies need to deploy thousands of servers. Paying for a RHEL subscription for each one would be incredibly expensive. Using a free, compatible OS allows them to offer stable and affordable hosting plans to their customers. Both AlmaLinux and Rocky Linux are widely available on major cloud platforms like AWS, Microsoft Azure, and Google Cloud .
3. Startups and Small-to-Medium Businesses (SMBs)
For a new company watching its budget, saving on software licenses is a big deal. Using Rocky Linux or AlmaLinux allows them to invest their money in product development and hiring instead.
4. Universities and Research Institutions
Academic institutions often have limited budgets. Free, powerful operating systems are a perfect fit for powering research computations, running university websites, and teaching students about enterprise-grade IT systems. Scientific Linux was a classic example of this, built by and for research labs .
5. Government Agencies
Governments around the world are increasingly adopting open-source software for reasons of security, cost, and independence. Stable, secure Linux distributions are a key part of this shift.
The Future: What Lies Ahead?
The ecosystem of RHEL-based distributions is more dynamic than ever. The events of 2020 and 2023 proved that the community values choice and freedom highly enough to build and maintain its own alternatives.
We are likely to see:
- Continued Competition and Innovation: The friendly competition between AlmaLinux and Rocky Linux will continue to drive both projects to improve, benefiting all users.
- Further Specialization: We may see new distros emerge that are tailored for specific new technologies, like artificial intelligence (AI) or edge computing.
- An Evolving Relationship with Red Hat: The relationship between Red Hat and the clone communities will continue to be complex. Red Hat’s recent source code changes have made rebuilding more difficult, but as we’ve seen, the community is resourceful and resilient.
One thing is for sure: the demand for free, enterprise-grade Linux is not going away. The story of AlmaLinux, Rocky Linux, and their siblings is a powerful testament to the strength and spirit of the open-source community. When a door closed with CentOS, the community didn’t just complain—it built two new, better doors, and ensured that everyone has a key.
Conclusion
The world of RHEL-based Linux distributions is a fascinating example of how open-source software evolves to meet the needs of its users. From the shock of CentOS’s change to the rise of AlmaLinux and Rocky Linux, this journey shows that collaboration and competition can coexist to create robust, reliable, and free alternatives for everyone.
Whether you are a student, a developer, a system administrator, or a business owner, these distributions offer a powerful platform to build, learn, and grow. They ensure that the stability and security of enterprise Linux remain accessible to all, fostering innovation and preventing any single company from having too much control.
So the next time you hear about AlmaLinux or Rocky Linux, you’ll know that they are more than just free versions of Red Hat. They are community-driven projects that ensure freedom, choice, and stability in the world of enterprise computing.