PdfMerge is an Open Source software that enables you to merge multiple PDF documents into a single file. You can specify the range of pages to extract, set a bookmark for each document, provide individual document titles, and arrange the order of the files to be merged. You can add files to the list by drag and drop or import command files that contain a list of the documents and processing instructions (requires some basic text or XML editing). A command line interface is also included for advanced users. The current version does not support password protected PDF files.

The license of this software is Freeware, you can free download and free use this pdf software.