Markdown
Plain text to HTML convertor, relying on standardised but natural formatting syntax in the plain text.
http://daringfireball.net/projects/markdown/

PrivyPad
A text editor that allows to create, edit, read and e-mail plain or encrypted text files. Uses BlowFish, Xor, 3Des and Rijndael encryption algorithms to scramble the text.
http://www.slavasoft.com/privypad/

Plain Language Service
Canadian service which conducts workshops on clear verbal communication and plain language, offers plain language revisions as well as translations of text from English to French.
http://www.pls.cpha.ca/

Retypar
The world's largest development and download repository of Open Source code and applications
http://sourceforge.net/projects/retypar

Motion Message Inc.
Manufacturers since 1978 of LED Signs, Text Panels, Graphics Signs, Single Line LED Signs, Custom LED Displays, Indoor and Outdoor LED Displays, LED Displays & LED Signs
http://motionmessage.com

Eddy
Are you a kid or a new computer user who wants a simple word processor? One without the pull down and right click menus? Oversize buttons
http://www.testedok.com/eddy.html

Seven habits of effective text editing
Guidelines and hints for editing plain text more quickly and with fewer mistakes by Bram Moolenaar.
http://www.moolenaar.net/habits.html

Glori Anon
An easy to understand tutorial on the use of Paint Shop Pro 5.0,plain speaking text with screen shots to demonstrate the text tutorials.
http://www.glorianon.com/psp/

RFC 2646: The Text/Plain Format Parameter
Now-obsolete specification of the "Format=Flowed" solution to reflowing paragraphs in text files.
http://tools.ietf.org/html/rfc2646

EditorPro
Multi-tabbed text editor for plain text file editing, or use with full color syntax highlighting, and code handling features for 9 different programming languages, and multiple file types, HTML, Visual Basic, and databases.
http://www.dcalcoda.com/editorpro.html