Minimalist tools for writers by Dmitri Popov on Linux.com:

Doing word processing without a dedicated word processor may seem like an absurd idea, but it actually makes a lot of sense, as long as you have the right set of writing tools — a solid text editor, the txt2tags utility, and Aspell spelling software.

Of course, the point isn’t to use the three specific tools he mentions, but rather plaintext as an ideal system for writing. In the comments, for example, someone brings up the plainer-than-thou nano editor, which does one thing really well: takes the text that you type, lets you move it around on screen a bit, and then lets you save it in a file. That’s it. :)