I created a very simple RTF viewing library, called SDL_rtf.
It loads RTF files, and allows you to display them in any surface.
It’s really rough, but you can check out the beginnings at:
http://www.libsdl.org/cvs/SDL_rtf-0.0.1.tar.gz
You need to provide your own font routines. The example 'showrtf’
uses SDL_ttf for it’s font handling.
So far it supports font sizes/colors/styles, justification, tabs,
and indentation. It doesn’t support tables or page layout yet.
When the display area changes size, the text is automatically
reflowed to match. 
Bug fixes, improvements, comments welcome.
See ya!
-Sam Lantinga, Software Engineer, Blizzard Entertainment