RTF format means Rich Text Format and is developed by MicroSoft. Most major text processing programs can read it, both on Mac and IBM/PC. For example, it works with WordPerfect on a PC.
The manual exists in the following types (931208):
The first you uncompress, un-binhex and read into MS Word; the second you uncompress and print from your Unix box; the third you uncompress and read into any word processor which recognizes the format.