PDFedit is a free PDF editor for Unix-like operating systems (including Cygwin on top of Windows). It does not support editing protected or encrypted PDF files or word processor-style text manipulation.
License: Open Source
ScanTailor is primarily focused on the post-processing of scanned images, enhancing them for output, while PDFedit is geared towards editing and managing PDF documents. Both are open-source and free, but they cater to different needs in terms of image processing and PDF editing.