Azure Linux 4.0 is Microsoft's first general-purpose Linux

Microsoft's Azure Linux 4.0, now in public preview, marks a strategic shift from a specialized container host OS to a general-purpose Linux distribution available across all Azure compute platforms (VMs, containers, AKS, WSL), with modernized components (Fedora 43 base, dnf5 package manager, kernel 6.18 LTS) and enterprise-grade security including FIPS 140-3 certification. This move reflects Microsoft's 15-year evolution toward Linux-first cloud infrastructure, with over two-thirds of Azure customer cores already running Linux, positioning the company to compete directly with AWS Linux and Red Hat while offering cost advantages and supply chain transparency. IT organizations now have a Microsoft-backed, audit-friendly Linux option optimized for cloud workloads that reduces vendor lock-in concerns while maintaining deep Azure integration for hybrid and cloud-native deployments.