With Docker and now Windows Subsystem for Linux, the software development under Linux is enough to be tested on Windows.
Even Microsoft cannot resist the open source (Linux) movement.
The Windows Subsystem for Linux does two main things:It enables with Windows NT kernel to understand the ELF binary format, and translate it, as closely as possible, to the binary format used by Windows.It implements a sizeable subset of the POSIX system call standard on top of Windows. Although Windows’ own system calls do not map directly the POSIX, because Microsoft has access to how its underlying operating system is implemented, they are able to implement the POSIX interface on top of the lower-level details of their NT kernel.WSL also provides its own bash shell–a command-line interface favored by many users of Linux. This provides a UNIX-like command-line interface within Windows, also has an underlying system for transparently translating things like file paths between the Windows and UNIX formats.The ultimate goal is to be able to take a program compiled and built on a Linux system, copy it over to Windows, and allow it to run without any modifications, with all the system-level translations completely transparent to the user. Targeting Linux software specifically makes this possible, because the system interfaces it will use are well-specified predictable in most cases. This is as opposed to running a virtual machine, in which an entire separate operating system is run in order to run software on that OS, and which needs to be able to run any arbitrary OS.This is direct support for Linux software in Windows itself–there is no virtualization.