Fedora-based, on GitHub here: https://github.com/microsoft/azurelinux

An open-source Linux distribution built and optimized for Azure, with sources derived from Fedora Linux. Azure Linux provides a secured, reliable operating system for virtual machines, containers, and bare-metal platforms.

Azure Linux is built on a robust open-source foundation and enhanced with Azure-specific innovations. This provides the familiarity of the RPM package ecosystem, while adding Azure-native security, compliance, and operational capabilities.

Key features of Azure Linux include: hardened security posture, an Azure-optimized kernel, supply chain security, native Azure integration, and a predictable lifecycle.