Microsoft has released Azure Linux 4.0, transitioning it from an internal tool to a server operating system that users can install on their own servers and virtual machines. Azure Linux 4.0 is built on Fedora Linux, allowing the use of RPMs and ensuring compatibility with Azure's cloud platform. The beta version features a hardened Linux kernel 6.18, optimized for performance on Hyper-V and Azure virtual machines, and incorporates SELinux-based security measures without a graphical user interface. In the Azure Marketplace, it is marketed as a "Microsoft-built Linux distribution for Azure," with formal support available for deployments on Azure but not for standalone hardware. The Azure Linux GitHub repository provides transparency into the distribution, encouraging community engagement while Microsoft retains control over the base image's contents. Azure Linux is positioned as a free, Azure-optimized server operating system for hybrid environments, potentially signaling a shift away from Windows Server.