Rich Text Format (RTF) is a format that can be understood by many different word processing programs. It is useful in situations where a document must be shared between people with different word processing programs. You can convert a document to RTF when you save it. To do so, when you save the document, you must indicate that you want to save it as a RTF document. You should check with "Help" feature of your word processing program to find specific instructions on how this is done.
Word processing programs that support RTF for PC's include Microsoft Word and Works, as well as Open Office. For Macintosh, Open Office, Mariner Write, and Nisus Writer XP support RTF.