Red Hat Inc.’s announcement last month that it would impose restrictions on the availability of source code for its Red Hat Enterprise Linux operating system created a stir among developers and Linux users who have relied on no-cost alternatives AlmaLinux and Rocky Linux, which were built to be “bug-for-bug compatible” with RHEL.

Red Hat’s decision means clones can no longer promise that they will run software written for the latest release of RHEL, because Red Hat’s new restrictions allow source code only for paying customers or developers who agree not to redistribute it. Previously the code had been available to anyone.

Not to worry, though, said benny Vasquez (pictured), chair of the AlmaLinux OS Foundation, a nonprofit that oversees the development and licensing of the popular community-built platform. “For typical users, there’s very, very little difference,” she told SiliconANGLE. “Overall, we’re still exactly the same way we were, except for kernel updates.”

Updates may no longer be available the day a new version of RHEL comes out, but developers still have access to Red Hat’s planned enhancements and bug fixes via CentOS Stream, a version of RHEL that Red Hat uses as essentially a test bed for new features that might later be incorporated into its flagship product.

Almost as good

From a practical perspective, that’s nearly as good as having access to the production source code, Vasquez said. “While there is a generally accepted understanding that not everything in CentOS Stream will end up in RHEL, that’s not how it works in practice,” she said. “I can’t think of anything they have shipped in RHEL that wasn’t in Stream first.”

That’s still no guarantee, but the workarounds AlmaLinux has put in place over the past month should address all but the most outlier cases, Vasquez said. The strategy has shifted from bug-for-bug compatibility to being application binary interface-compatible.

ABI is a low-level set of machine code instructions that defines how applications interact with external libraries. While application program interfaces often change, developers generally keep ABIs stable because of their potential to cause disruption. ABI compatibility doesn’t guarantee that problems will never occur, but glitches should be rare and can usually be resolved by recompiling the source code.

“It is sufficient for us to be ABI-compatible with RHEL,” Vasquez said. “The most important thing is that this allows our community to feel stability.”

Windfall

In fact, Red Hat’s change of direction has been a blessing in disguise for AlmaLinux, she said. “When you’re essentially duplicating somebody else’s code all the time, there are few decisions that must be made around the technology,” she said. “We view this as a release from our bonds of being one-to-one.” Patches can be applied without waiting for a cue from Red Hat and “we get to engage with our community in a completely new and exciting way.”

AlmaLinux has also seen a modest financial windfall from Red Hat’s decision. “The outpouring of support has been pretty impressive,” Vasquez said. “People have shown up for event staffing and website maintenance and infrastructure management and we’ve gotten more financial backing from corporations.” She wouldn’t specify the size of the donations received, but she added that “the number of everyday people throwing in $5 has more than quadrupled.”

The bottom line is that users of AlmaLinux and other RHEL-compatible distributions need not worry about being marooned, Vasquez said. “We’re going to continue to have the support we need from both a code and a financial perspective,” she said. “More and more vendors are reaching out to ensure that their customers feel supported whether they use AlmaLinux or one of the other clones.”

Photo: AlmaLinux