PDF Architect!

PDFsam Basic is a free, open source, multi-platform software designed to:

Make your job easier with Adobe Acrobat DC, the trusted PDF creator. Use Acrobat to convert, edit, and sign PDF files at your desk or on the go.

Nitro Pro gives you everything you need to create, convert, edit, sign, and share 100% industry-standard PDF files. It's simple, straightforward, and intuitive to use — so you can work more productively, your way.

PDF Chain is a GUI for pdftk written with gtkmm. You can merge some pdf files to one pdf file or split, set background/stamp or add attachments to one pdf file. There are also some options and tools.

Free (and open source) editor for manipulating PDF documents. GUI version + commandline interface. Scripting is used to a great extent in editor and almost anything can be scripted, it is possible to create own scripts or plugins.

jPDF Tweak is a Swiss Army Knife GUI application for PDF documents: combine, split, rotate, reorder (n-up, booklet), watermark, edit bookmarks/fileinfo/pagetransition, compress, encrypt, decrypt, sign, repair, edit attachments and more.

Sejda helps with your PDF tasks with a simpler, more pleasant and productive PDF platform.

UnityPDF lets you merge, split, divide, rotate, protect PDF files and more. All features are easy to use and do not require complex skills.

PDFescape is your free, online PDF reader, editor, form filler, & form designer. Without required downloads or installations! Without watermarks! Without required registration! * Open PDF Files from your local computer * View PDF Files discovered on the web * Fill Out PDF Forms using PDF form fields * Forget Hand Writing with the typewriter style tool & complete non-fillable forms * Edit PDF files & forms o Add Text & Shapes to PDF files, allowing customization & markup of PDF o Move & Delete Pages in PDF files. »

PrimoPDF is a handy and lightweight utility that converts just about any file type to a PDF by using the source program that created the file and its Print command. The conversion process is quick and efficient, bolstered by a clean, simple interface. The included security features allow you to wrap your PDF in 40-bit or 128-bit encryption, and there's PDF merging and password protection, too. The user also can restrict editing to basic interactions such as comment-making.

iSafePDF is a free open source PDF protection software.

Wondershare PDFelement is a professional PDF tool that enables users to edit text, images, objects on PDF, merger or split a PDF file, convert PDF to MS Word, edit and fill out PDF forms.

Wide Angle PDF Converter is a Windows application, which allows users to manage, convert and secure their PDF files, all in one place. All conversions and PDF file management are performed locally, so there is no need to upload sensitive documents to the web. Wide Angle PDF Converter enables its users to securely convert PDF documents to a variety of formats including Word, Power Point and Excel. PDF files can also be converted to mages such as JPG, PNG, SVG and GIF, as well as to other formats such as TXT, HTML, EPUB, XPS and PostScript. Additionally PDF files can also be secured using the software, password protection added, permissions for collaborators set and watermarks added. Multiple PDF documents can be merged or split into individual PDF files. This comprehensive PDF manager also enables users to add bookmarks and attachments for easy navigation and file sharing, as well as export selected text or images from PDFs for use in other applications or documents. Wide Angle PDF converter is available as a free demo download enabling users to convert or modify two of their PDF files. The full version of the software allows users to install the software on two computers and use it indefinitely. The software is updated regularly and product updates as well as friendly customer support are provided free of charge. »

Ultra PDF Merger is a freeware PDF utility that joins your PDF files, or part of them, together. It is a windows application and it runs on both 32bit and 64bit systems. Ultra PDF Merger is portable which means you don’t have to install anything, just download it, extract its content and run it. In this way you can put it in your USB drive and use it anywhere.