Microsoft announced Azure Linux 4.0 and the general availability of Azure Container Linux at Open Source Summit North America 2026. Azure Linux 4.0 expands beyond its container-focused origins into broader server workloads, built on a Fedora upstream base with Python 3.12 and a new pylock sandboxing capability for isolated Python environments. Azure Container Linux targets containerized and regulated enterprise workloads with an immutable, reduced-attack-surface design. Microsoft also highlighted its involvement in the Agentic AI Foundation, introduced an open-source Agent Sandbox Runtime based on Firecracker micro-VM technology, and reaffirmed support for supply chain security initiatives like OpenSSF. Over two-thirds of Azure customer cores now run Linux workloads, with Linux underpinning ChatGPT, GitHub, and Microsoft 365.
