Westfield State College Writer's Guide
WYSISYG front ends to TEX are available, including Scientific Workplace which combines TEX with the powerful symbolic algebra system MAPLE. Symbolic algebra systems like MAPLE and Mathematica have built into their most recent versions fairly sophisticated WYSIWYG mathematical typesetting capabilities.
Rudimentary mathematical typesetting and wordprocessing (e.g. subscripts and superscripts, some Greek letters, and some mathematical symbols) can be done on standard wordprocessors like Microsoft Word and WordPerfect.
There is a new WYSIWYG program called MathType that is designed to sit "on top" of "any Macintosh or Windows wordprocessor" and deliver "publication quality equations".