PDF Split Merge Extract is a free software application that performs exactly what its name suggests – it allows you to split a single pre-existing PDF file into smaller files containing one page each, to merge two PDF source files into a single one, and to extract as many pages as needed into a separate PDF file.
All of the processes mentioned above are carried out quickly and clean. The program presents three separate tabs, one for each function. When splitting PDF files, you are allowed to choose whether to create one file for every single page in the document, a file for every fixed number of pages, or a new document containing only certain pages or subsets of pages (in the same way you specify in Microsoft Word the pages you want to send to the printer). The merge function is, unfortunately, limited to two source files. Finally, in the extract option you can choose from which to which page of an existing PDF file you want to extract, and the program will put them on a new PDF file.
PDF Split Merge Extract is very good at doing what it does. However, it does not include any help files describing the functions it provides, and/or its usage. For example, the extract function usefulness is not very clear, as it could be perfectly covered by the split function. Nevertheless, I guess its actual usage would be to extract pages from protected or encoded PDF files.