This program lets you create a booklet out of a PDF file, which is known as pages imposition. It is a useful tool to reduce the number of pages that has to be printed, which lets you save a lot of paper. A booklet is book that is bound in the middle. Which means that a booklet has four pages printed on one sheet of paper (two on each sides). If you have for example a PDF file with 8 pages, your booklet will look like this: • First sheet, first side: pages 8 and 1 • First sheet, second side: pages 2 and 7 • Second sheet, first side: pages 6 and 3 • Second sheet, second side: pages 4 and 5 The bottom line is that you simply print your booklet, staple it by the middle, fold it in two and you have a book. CocoaBooklet also lets you create a minibooklet. This is especially useful for printers that cannot print on both sides. In addition, CocoaBooklet can be setup as a PDF service. Thus, when you print a document (from your favorite browser or text editor or whatever) you will find a button that gives you the opportunity to create a PDF file but also to directly create a booklet. Cocoabooklet appears to be discontinued, but it can still be downloaded from MacUpdate (http://www.macupdate.com/app/mac/14804/cocoabooklet ) & Softpedia (http://mac.softpedia.com/get/DTP-Prepress/CocoaBooklet.shtml ).