Microsoft's Linux U-Turn Continues With Its Own Azure Linux Distribution

Microsoft has released Azure Linux 4.0 in public preview earlier this month, introducing a redesigned architecture, updated software stack, and tighter integration with the Fedora ecosystem. The release highlights how far the company has come since its former anti-Linux stance, with Linux now powering the majority of workloads running on Azure, as Windows Latest reports.

Azure Linux is Microsoft’s own open-source Linux distribution, built specifically for cloud infrastructure rather than desktop PCs. While it has quietly powered several Microsoft services for years, version 4.0 brings major changes that should make the platform easier to maintain and more attractive to enterprise customers.

Azure Linux 4.0 moves to a Fedora-based architecture

Azure Linux 4.0 became publicly available around Microsoft Build 2026 as the next major version of Microsoft’s cloud-focused operating system.

The distribution already powers several Microsoft services, including Azure Kubernetes Service (AKS), Azure SQL, and Azure Cosmos DB. It has also seen adoption by major customers. LinkedIn previously migrated its infrastructure to Azure Linux 3, while Databricks moved more than 100,000 virtual machines and over one million CPU cores to the platform.

One of the biggest changes in Azure Linux 4.0 is how Microsoft builds the operating system. Earlier versions assembled packages individually, but Azure Linux 4.0 is now built as a documented set of overlays on top of Fedora 43. This allows Microsoft to stay closer to upstream Fedora while simplifying development and maintenance.

The distribution also switches to dnf5, the latest version of Fedora’s package manager, bringing Azure Linux in line with the modern RPM ecosystem used by Fedora and Red Hat Enterprise Linux.

Built for Azure, not the desktop

Unlike Ubuntu Desktop or Fedora Workstation, Azure Linux 4.0 is not intended for everyday desktop use.

It ships without a graphical interface, desktop environment, audio stack, or consumer applications. Instead, Microsoft includes only the components required for server and cloud workloads.

The minimal approach reduces the operating system’s attack surface, improves predictability, and makes monthly security updates easier to manage.

Although Azure Linux can technically run outside Azure, Microsoft does not officially support deployments outside its cloud platform.

Modern software stack with post-quantum security

The Azure Linux 4.0 public preview includes several major software upgrades.

Among the key components are Linux kernel 6.18 LTS, glibc 2.42, systemd 258, Python 3.14, OpenSSL 3.5, and enhanced Hyper-V integration.

OpenSSL 3.5 adds support for post-quantum cryptography algorithms, including CRYSTALS-Kyber and CRYSTALS-Dilithium. These algorithms are designed to help organizations prepare for future quantum computing threats.

Microsoft also said FIPS 140-3 certification is still underway and is expected closer to the operating system’s general availability release.

Azure Container Linux targets container workloads

Alongside Azure Linux 4.0, Microsoft introduced Azure Container Linux, an immutable operating system built specifically for container environments.

Instead of updating individual packages, Azure Container Linux replaces the entire operating system image during updates. If an update causes problems, administrators can roll back to a previous version.

This design improves reliability while reducing configuration drift across large-scale deployments.

Why Microsoft built its own Linux distribution

Linux has become the most widely used operating system on Azure, making it increasingly important for Microsoft to control more of its cloud software stack.

Maintaining its own Linux distribution gives Microsoft greater control over security updates, package signing, software bill of materials (SBOMs), and enterprise supply chain requirements.

In related Microsoft news, the company is facing a lawsuit related to Azure’s cloud business. Microsoft CEO Satya Nadella also recently said the future of AI should not belong to only a handful of companies, while Microsoft AI CEO Mustafa Suleyman said artificial intelligence is designed to help workers become more productive rather than replace them.