A lot of folks who use applications that save files in their own
formats, (MS Word and PowerPoint, OpenOffice Writer, SunOffice, etc.)
tend to forget that not everyone has software that’s able to open
them. This is understandable, especially if you work at a job where
everyone else uses the same applications, and clearly someone who has
worked hard to produce a great .ppt presentation would be disinclined
to take it apart and put it back together in a different format so she
can send it to Cousin Jethro, who’s still plugging along with his old
Works 2000 suite. Some folks (like me) won’t accept documents in
the .doc format at all, because it is possible to include potentially
harmful files as part of the .doc file.

There are solutions - simple ones - to most of these problems. In the
case of documents, there is the Rich Text Format, (.rtf) common to
just about every word processor, regardless of pedigree. Just click
“menu,” “save as,” and select “.rtf.” You may lose some formatting,
but just about anyone you can send it to will have a program that can
open it. (If your word processing application won’t save in .rtf,
look here for a good free one
that will.)

The answer for PowerPoint (.ppt and similar) files is Microsoft’s own
PowerPoint Viewer 2003. This
application will run on Windows machines. A similar one is available
here for Macs - in fact, there
are several programs that will enable a Mac user to open various
Microsoft formats. Could be handy.