Scribus is an Open Source program that brings professional page layout to Linux/UNIX, Mac OS X, OS/2 Warp 4/eComStation and Windows desktops with a combination of press-ready output and new approaches to page design.
Underneath a modern and user-friendly interface, Scribus supports professional publishing features, such as color separations, CMYK and Spot Color support, ICC color management, and versatile PDF creation.
The above introduction is from http://www.scribus.net/canvas/Scribus
