ExifTool by Phil Harvey - "ExifTool is a Perl module with an included command-line application for reading and writing meta information in image, audio and video files. It recognizes EXIF, GPS, IPTC, XMP, JFIF, GeoTIFF, ICC Profile, Photoshop IRB, AFCP and ID3 meta information as well as the maker notes of many digital cameras including Canon, Casio, FujiFilm, JVC/Victor, Kodak, Leaf, Minolta/Konica-Minolta, Nikon, Olympus/Epson, Panasonic/Leica, Pentax/Asahi, Ricoh, Sanyo and Sigma/Foveon."
F-Spot - "F-Spot is a full-featured personal photo management application for the GNOME desktop. F-Spot simplifies digital photography by providing intuitive tools to help you share, touch-up, find and organize your images. "
jigl - Jason's Image Gallery - "jigl (pronounced jiggle) is a perl script that generates a static html photo gallery from one or more directories of gif/jpg/png images. It supports themes and is very customizable. It includes the ability to display comments and EXIF info for each image in a simple clean layout."
UFRaw - The Unidentified Flying Raw (UFRaw) is a utility to read and manipulate raw images from digital cameras. It can be used on its own or as a Gimp plug-in.