From Scribus Public Wiki
There is a doc on the Scribus web site, but it is partly outdated for current releases. The fastest way to get Scribus on the Mac is the following:
[edit] Installation
* Install the Xcode developer tools from
http://developer.apple.com/technology/xcode.html
* Install Apple's X11 (two packages, X11User.pkg from the system disk and X11SDK.pkg from the developer tools disk, the names may be slightly different). Note: The Xcode developer tools may install the X11 packages. In this case you can skip this step.
* Install Fink using the "Fink-X.Y.Z-ABC-Installer.dmg" from
http://fink.sourceforge.net (where X.Y.Z is the latest stable version and ABC is is either PowerPC or Intel depending on your system)
* For Version 1.3.3 - Open a terminal window then type:
fink install scribus
* For Version 1.3.4 - Open a terminal window
Enable unstable packages (accept all default options --by pressing enter-- except to enable the "Unstable" tree):
fink configure
fink selfupdate-rsync
Install 1.3.4
fink install scribus134-aqua
Optional: type the following to see a list of scribus versions (as this article may not be updated often enough to get new versions):
fink list scribus
When the list is displayed you can alternatively type:
fink install <name of package from the list>
* fink may prompt you to select certain packages based on dependencies it needs to install scribus. Accept any of the choices and continue.
* Sit back, drink some coffee and wait for the installation to finish.
* Once installation is complete you can run scribus by opening a terminal window and typing:
scribus