XyWrite

XyWrite was a word processor for MS-DOS that enjoyed a certain level of popularity in the late 1980s. Perhaps its greatest virtue was that its file format consisted of plain ASCII, which made it a favourite among typesetters who needed to convert various formats to LaTeX.

A Windows version was eventually produced, but failed to capture significant market share. A descendant of XyWrite called NotaBene http://www.notabene.com is still available, however, and enjoys some popularity among theologians who use Greek and Hebrew characters in their work.

Read about XyWrite from a developer at http://www.escape.com/~yesss/_xywhat.htm