如何開出 "rtf" file?

用 MS Word 就得啦！

Start→Run→↓
┌wordpad←─
∣
↓
╓─────╖
╟ENTER←┘∥
╙─────╜

Most word processing software implementations support RTF format import and export, often making it a "common" format between otherwise incompatible word processing software.
The WordPad editor in Microsoft Windows creates RTF files by default. It once defaulted to the Microsoft Word file format, but write support for Word documents was dropped in a security update.
The free software/open-source word processors AbiWord and OpenOffice.org can view and edit RTF files.
The default editor for Mac OS X, TextEdit, can also view and edit RTF files.
Since RTF files are text files, it’s easy to produce RTF with many programming languages, like Perl, Java, C++, Pascal, COBOL, or Lisp. Perl, for example, has the RTF::Writer module for this