One of Microsoft's top engineers, Mark Russinovich, has stated it's definitely possible that Microsoft will opensource its Windows operating system. According to Russinovich the changing software landscape forces companies like Microsoft to make such a move.
In an interview with Wired he states that Microsoft is a different company compared to a couple of years ago. He also states that in his eyes it's not unimaginable that the software giant will open source Windows in time. He doesn't mention anything on a timeframe and the CTO of the Azure platform emphasizes that in case Microsoft makes the move, it won't be an easy one. The complex Windows source code would need to be accompanied with well written documentation and solid development tools.
In the eyes of Russinovich an open source version of Windows could still contribute to Microsoft's revenues because it can sell support like companies as Red Hat and Canonical currently offer for Linux. This would increasingly make Microsoft a service providing company, certainly when the many cloud services the company offers are also taken in account.
A considerable part of Microsoft's revenue is still generated by selling Windows licenses but these earning are heavily under pressure. More and more companies are switching to open source software that mainly runs on Linux servers. Also Android, world's most used mobile operating system, is open source and runs on a Linux kernel.
After Satya Nadella became CEO of the company last year, Microsoft has started to embrace open source software. The company has announced a free to use Windows for Internet of Things although the source code will probably not be released. Microsoft also open sourced .NET hoping the application framework would gain more popularity. Also its Azure cloud platform currently allows running Linux Virtual Machines.
