Cross-platform command-line tool for creation of PDF documents from scans/photos of pages in JPEG (.jpg) format and the lightest weight ANSI C library to put multiple JPEG files into one PDF file.
You can add handwritten comments to PDF scans (over original images) with xournal: http://xournal.sourceforge.net/
It supports graphics tablets and saves comments to PDFs as vector data.
Really useful, but not intended for the average computer user. User needs some programming skills. A GUI would help much.
Super programme, merci pour le partage ! ;)