Linux distributions from Microsoft include a project known as Azure Cloud Switch (ACS) released in 2015. Linux is used as a part of Azure infrastructure for reasons not disclosed by Microsoft. With the support for Microsoft SQL Server for Linux, Microsoft itself required internal Linux support, which uses its own distributions for this purpose.
In the past, Microsoft has strategically excluded any support for Linux due to it being a competitor operating system. However, as its partners have gradually embraced multiple technologies, the partnership became inevitable, where Canonical Ltd., backer of Ubuntu was hired in to provide support in the area, by providing a system to run Ubuntu natively on Windows 10.
SONIC
Software for Open Networking in the Cloud (SONIC) is a collection of network software components that runs on Debian. It was released on 9 March 2016. The software collection is designed to be run on top of layer 3 network devices such as some network switches.