gPhoto is a program and library framework that lets users download pictures from their digital cameras. The libgphoto2 library gives you access to hundreds of models of digital cameras on several platforms. GIT repo and Issue tracker lives at https://github.com/gphoto/ these days.
PDFView is a simple, yet powerful, Mac Os X PDF viewer, with advanced integration with LaTeX.
LinPHA is an easy to use, multilingual, flexible photo/image archive/album/gallery written in PHP. It uses a SQL database to store information about your pictures. It comes with a HTML based installer, so you don't need experience in setting up SQL
Full featured photo collection PHP script - Light, fast and easy to install.
Mig is designed to be a simple but flexible program that enables users to manage online photo galleries.