Update: Dark Room is the Windows equivalent of WriteRoom. Thanks to those who wrote in to tell me as much.
A few months ago I put the following in a bit:
WriteRoom is "for Mac users who enjoy the simplicity of a typewriter, but live in the digital world. [It's] is a full screen, distraction free, writing environment." I love this application and can see myself using it a lot. It's kind of like megazoomer, except that WR is itself an editor.
Indeed, earlier today I began drafting a patent application and found it to be indispensable. Is anyone aware of a similar application for Windows? I think I may want something like this at the office.