PDF Arranger - Small python-gtk application, which helps the user to merge or split pdf documents and rotate, crop...
PDF Joiner - This online tool allows you to join several PDF documents into a single file, free of charge.
PDF-XChange Editor - The smallest, fastest, most feature-rich PDF editor/viewer available
PDFChef Merge PDF - PDFChef Merge PDF is an online tool that allows you to merge multiple PDf files into one quickly and securely.
Master PDF Editor - Master PDF Editor is complete solution for editing PDF and XPS files.
PDFill - Open, View, Edit, Save and Print PDF Documents without Adobe Acrobat