I have become aware of the existence of a program called WSL (Windows Subsystem for Linux) in recent moths by suggestion of colleague.

There is no installation required, just enable it from ‘Control Panel -> Programs -> Turn Windows features on or off’.

It is simple/lightweight linux and designed to run simple linux commands and programs at windows. Why? Because it’s not an emulator. The emulator is called running one environment/operating system in another one. This is basically converter and converts linux/windows system calls to each other. For example, for a linux program, firstly linux system calls are converted windows system calls. Then, windows kernel response is converted linux kernel response. The program acts as it were running on the linux kernel. But, there are some limitations as you can image. The whole linux system calls must be implemented as windows system calls. You can’t use for complex programs which require heavy workload.

Nevertheless, it helps me in some cases. For example, I used redis (only works on linux) last weeks without virtual machine or docker.