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.
Coin is an implementation of Open Inventor. Open Inventor is the de facto standard API for retained-mode 3D graphics programming. Open Inventor has a highly extensible design, and has been designed to allow for rapid development of highly interactive 3D graphics applications in the fields of CAD, engineering, scientific computing, simulation, VRML, and visualization.
GIMP is the GNU Image Manipulation Program. It is a freely distributed piece of software suitable for such tasks as photo retouching, image composition and image authoring. It can be used as a simple paint program, an expert quality photo retouching program, an online batch processing system, a mass production image renderer, a image format converter, etc.
Image Viewer is a multi-frame (animated) image viewer with real-time interactive pan and zoom viewing that uses the GTK+ toolkit and Imlib. It is capable of opening and saving to any image format supported by Imlib. It features screenshots (screen capture), crop, resizing, print, fullscreen display, display on the desktop (root window), animation (creating animated GIFs), color leveling, drawing font/text strings, and editing image header information.
DjVu is a Web-centric format and software platform for distributing documents and images. DjVu content downloads and displays faster than competing formats. DjVu images can be smoothly zoomed and panned. DjVuLibre is an open source implementation of DjVu, including viewers, browser plugins, decoders, simple encoders, and utilities.