jPDF Tweak is a Java Swing application that can combine, split, rotate, reorder, watermark, encrypt, sign, and otherwise tweak PDF files. Developed by Michael Schierl
License: Open Source
jPdf Tweak is a lightweight and user-friendly tool primarily focused on basic PDF manipulation tasks, while PDFsam offers a more comprehensive set of features for advanced users, including annotations and form filling. Both are open-source and provide cross-platform support, but PDFsam may have a steeper learning curve due to its extensive functionalities.