Split and Merge PDF Document with pdfsam

pdfsam is an open source tool (GPL license) designed to handle pdf files. It requiers a Java Virtual Machine 1.4.2 or higher and it’s released in 2 versions, basic and enhanced.
pdfsam basic:
A simple tool designed to split and merge pdf files. With it’s simple and intuitive interface you can:
* split your pdf documents (into chapters, single pages, etc.).
* merge many pdf documents or subsections of them.
* extract sections of your document into a single pdf document.
* mix alternate pages taken from two pdf documents in straight or reverse order into a single document.
* save and load your environment to automatize your recurrent jobs.
* manage pdfsam settings and set an environment to load at start up.
pdfsam enhanced:
This is the enhanced version of pdfsam. In this version you’ll find all the basic features plus:
* encrypt your pdf files (RC40 bits, RC128 bits, AES128 bits) and set permissions on them.
* add a pdf frontpage or an addendum (or both) to your pdf documents.
* decrypt pdf documents.
* extract attachments from your pdf documents.
* set viewer options to a document to tell the viewer application how should open the document.
for details, please visit here.