Microsoft's new Azure Linux 4.0 is here, and it could replace Windows Server in the enterprise

Microsoft has unveiled Azure Linux 4.0, marking a significant shift in its strategy by making this server distribution available as an installable ISO. Previously, Azure Linux was primarily an internal component optimized for Microsoft's own cloud infrastructure. Now, enterprises can download and deploy Azure Linux 4.0 on their own servers and virtual machines, extending its utility beyond the Azure cloud. This release positions Azure Linux as a strong contender to potentially replace Windows Server in certain enterprise scenarios, particularly for organizations operating in hybrid cloud environments. The distribution is based on Fedora Linux, with Microsoft curating packages and the supply chain to ensure optimal performance and integration within the Azure platform. It comes with a hardened Linux kernel 6.18 and is specifically tuned for Hyper-V and Azure VM performance. Key features of Azure Linux 4.0 include SELinux-based security, a default configuration tailored for cloud and server workloads, and integration with Azure security features like confidential computing and Defender for Cloud. While designed for Azure, Microsoft emphasizes that users can run it anywhere, just like any other Linux distribution. However, formal support and Service Level Agreements (SLAs) are provided when used within Azure, encouraging its adoption within Microsoft's cloud ecosystem. The availability of Azure Linux 4.0 as a standalone server distribution reflects Microsoft's recognition of Linux's growing dominance in cloud server environments. For nearly a decade, Linux has been the most popular server operating system on Azure, surpassing Windows Server. By offering a free, Azure-optimized server OS that also supports on-premises deployment, Microsoft aims to provide a unified Linux operating system experience across hybrid environments, thereby strengthening the integration between Linux and its comprehensive Azure stack. Additionally, Azure Linux for Windows Subsystem for Linux (WSL) will soon be available, enabling developers to work with it seamlessly on their workstations.