RTF is a document formatting language developed by Microsoft. There are many word processing packages (Microsoft Word, Word Perfect, Frame Maker...) that can read or write RTF format files. rtftohtml was designed to translate existing RTF documents into HTML - the format of the World Wide Web. rtftohtml can also be used to author new documents specifically for the WWW.
The specification for RTF and a set of filters for translating RTF to plain-text, troff and Tex and LaTex are available at: ftp://ftp.primate.wisc.edu/pub/RTF