PDFTK Builder - PDFTK Builder is a free graphical interface to for PDFTK, making it much easier to use.
PDF Password Remover Tool - PDF Password Remover Tool. Free PDF password remover tool by PDF Technologies. Remove passwords from PDF documents.
GSView - Use Ghostscript GSview to open PDF files with owner password restrictions.
Recover PDF Password - Recover PDF Password for Mac recovers forgotten passwords to PDF and unlocks PDF documents.
PyPDF2 - PyPDF2 - A utility to read and write pdfs with Python
Free Any Data Recovery - 100% Completely Free Data Recovery Software