It seems that Satya Nadella’s Microsoft is a very different animal than earlier Microsoft, unafraid to use any technology if it gets the job done: Article Microsoft has developed its own Linux. Repeat. Microsoft has developed its own Linux reports that Microsoft has developed its own Linux distribution to do Azure networking. Official Microsoft web page Microsoft showcases the Azure Cloud Switch (ACS) seems to verify that. So Microsoft has built something called Azure Cloud Switch (ACS), describing it as “a cross-platform modular operating system for data center networking built on Linux” and “our foray into building our own software for running network devices like switches.” ACS also allows Microsoft to share the same software stack across hardware from multiple switch vendors. This is done via the Switch Abstraction Interface (SAI) specification, the first open-standard C API for programming network switching ASICs, of the Open Compute Project (OCP).
Kamala Subramanian, Redmond’s principal architect for Azure Networking, writes that: “At Microsoft, we believe there are many excellent switch hardware platforms available on the market, with healthy competition between many vendors driving innovation, speed increases, and cost reductions.”
Software-defined networking (SDN) is a very fine idea. It appears Redmond couldn’t find SDN code to fits its particular needs, so it needed to built new system based on what rest of the industry is using. That experience clearly includes Linux, not Windows, as the path to SDN.