but there is an active effort (by Microsoft) to make it available for Windows also.
Interesting: Docker is developed in Go language.
podcast: Herding Code 202: Ahmet Alp Balkan on Docker
There are alternative containers tools for Windows:
Spoon.net Containers for Windows - Use your applications instantly, anywhere
Microsoft and Sphere3D To Develop Windows Containers for Azure -- Redmondmag.com