RTFGen, a RTF generator class for PHP, is a very powerful tool to create complex RTF files from PHP on the fly. You control all the aspects of the RTF document you are generating: pagination (orientation, numbering, size, etc), sections, paragraphs, all formatting properties (for paragraphs, pictures, tables), colors, styles, fonts, headers, footers, footnotes, endnotes, pictures, tables and much more. Because of its flexibility, this RTF generator could be used very well as document generation software within a document delivery application.

What is the RTF ?

The rich-text format (RTF) standard is a method of encoding formatted text and graphics for easy transfer between different programs and different operations.

The RTF Specification provides a format for text and graphics interchange that can be used with different output devices, operating environments, and operating systems. Generally, it is used by all Microsoft Word programs — Word for Windows, Word for the Macintosh, and Word for MS-DOS — for moving word-processing documents between different platforms without having to rely on special translation software or conversion utilities. RTF uses the ANSI, PC-8, Macintosh, or IBM PC character set to control the representation and formatting of a document, both on the screen and in print. With the RTF Specification, documents created under different operating systems and with different software applications can be transferred between those operating systems and applications.

RTF version 1.7 includes all new control words introduced by Microsoft Word for Windows 95 version 7.0, Word 97 for Windows, Word 98 for the Macintosh, Word 2000 for Windows, and Word 2002 for Windows, as well as other Microsoft products.
http://msdn.microsoft.com/library/specs/rtfspec.htm