Good Luck...

PROPRIETARY
If something is "proprietary", that simply means that someone owns it, which
is usually the case with software. But it usually implies that the owner
won't tell anyone else how it works, and tries to prevent other developers
from creating software that does the same thing. This becomes a problem when
something proprietary becomes a de facto (unofficial) standard. For example,
Microsoft Word is so common that people are now passing around Word-format
DOC files and expecting other people to be able to open them. But the DOC
format is proprietary (and keeps changing), so the developers of other word
processors have difficulty enabling their products to do something as simple
as opening DOC files. Microsoft is also fond of adopting official standards,
but then adding proprietary extensions, which then trap people into using
Microsoft's software rather than being able to use any software that
supports the true standard. This renders the standard useless. Their slogan
for this tactic is "embrace, extend, extinguish". (compare to: open source,
public domain, shareware)

... you might get a few clues from http://microsoft.toddverbeek.com/wp.html 
which amongst other things notes that:

When used together, WordPad and Word Viewer make up a "poor man's Microsoft
Word". WordPad is a bare-bones word processor that comes with Windows. It's
not much good for anything beyond simple letters or memos, but it reads and
writes documents in Word 6 format. Word Viewer is a free download from
Microsoft that can read and print Word 97 and most Word 2K/XP documents,
taking the burden off your word processor of choice if people are in the
habit of sending you documents in those formats.
icWord is a shareware utility for viewing Word documents on a Mac.

Regards,
Dave.