Free web software for signing PDFs and also organize pages
Edit, Convert, Extract , Export, Secure and PDF Imposition.
Enhanced version of the PDFTK Builder GUI for PDF Toolkit on Windows
Tile large format PNG patterns into print-at-home PDF pages
Electronic design and programming tools suite like Eagle, MpLab
STPA support tool
Add file name, watermark, and other text to PDFs in batch process
KDE servicemenu for pdf
.NET class library stamps, secures, and signs pdfs.