Windows because we use C# / ASP.NET MVC and Visual Studio / Resharper is a very productive combination. Our test and production machines are Linux/Mono however.

Windows because we use C# / ASP.NET MVC and Visual Studio / Resharper is a very productive combination. Our test and production machines are Linux/Mono however. Our system utilizes a number of services which are best run under Linux, in particular Redis. On our dev machines we use Vagrant / VirtualBox to host these. Git works fine under windows, and I find myself working in the git shell a lot for general tasks as well.