From what I can gather it all started with the OSX application WriteRoom, a seemingly (I’ve never tried it) excellent “distraction free” text editor. When I first heard of it I liked the idea, realized it was an OSX app, and moved on.
A while later I came across Dark Room, a WriteRoom clone for Win32. Still a bit annoyed over the lack of such an application for GNU/Linux I again moved on.
And then a couple of weeks ago, almost the same day, I heard about PyRoom from two different sources (I still maintain that the universe has a flaw in its random number generator ;)), and tried it out.
And I have to say, albeit the very spartan interface, and almost none of the power I find in Vim, PyRoom is perfect for its purpose. It is a distraction-free full-screen text editor, no more, no less.
I would never think of doing heavy text manipulation in PyRoom, Vim excels at that and enters the stage the second PyRoom has played its part, but for pure text creation, i.e. from in-head ideas to on-file text, PyRoom has no opposition.
For aptitude-enabled people
$ sudo aptitude install pyroom
will do the trick.