BRL-CAD is a powerful constructive solid geometry solid modeling system that includes an interactive geometry editor, ray-tracing support for rendering and geometric analysis, path-tracing for realistic image synthesis, network distributed framebuffer support, and image and signal-processing tools.
Jhead is a command line driven utility for extracting digital camera settings from the Exif format files used by many digital cameras. It handles the various confusing ways these can be expressed, and displays them as F-stop, shutter speed, etc. It is also able to reduce the size of digital camera JPEGs without loss of information, by deleting integral thumbnails that digital cameras put into the Exif header. If you need to add Exif support to a program, this is a simple program to cut and paste from. Many projects, including PHP, have reused code from this utility.
makethumbs is a Bourne shell script which creates static HTML image galleries suitable for web or CDROM presentations. It is designed for portability and depends on the fewest possible helper programs. You can simply run makethumbs in a directory of JPEGs and get a usable set of web pages. If you have the time, you can add captions, descriptions, and create a dotrc file to completely change the look and feel of the generated gallery. A small helper script, rotate.sh, is also available to easily fix rotated images.