SImg is a software for astronomical image processing. It contains a tool for visualization of highly dynamic images. The package consists of a library and applications which use it. Some of the features are deconvolution (various methods), Video4Linux support, PSF computation, approximation by linear combination of images and polynoms, various color transforms, automatic shifting of image sets (for addition and color composition), and more.
Grafx2 is a bitmap paint program that allows you to draw in more than 60 video resolutions (from 320x200 to 1024x768, including most of the standard Amiga resolutions: 320x256, 320x512, 640x256, 640x512, and more, provided your video card knows how to handle them). Its layout is not very different from the famous Deluxe Paint or Brilliance, so it will be quite easy to handle it if you know at least one of these programs.
MapMemo allows you to drag your files onto any graphic (map, photo, scan, illustration, screenshot, etc.), and thus give them a visual, location-based relation. It uses only aliases of your files which, when you click on an appropriate location, will open in their original application. You can use layers, info windows, colors, and comment fields to organize your files on the map.
Pixel is an application for editing, retouching, manipulating, and animating RGB, CMYK, and HDR images. It was formerly known as Pixel32. It is available for Windows, Linux, Linspire, Mac OS X, BeOS, Zeta, QNX, MorphOS, FreeBSD, eComStation, OS/2, SkyOS and even old plain DOS, for both x86 and PowerPC architectures.
SAGA GIS (System for Automated Geo-scientific Analysis) is a geographical information system (GIS). The SAGA GIS API supports grid data like digital terrain models and satellite images, vector data, and tables. This API makes it easy to implement new algorithms and exempts the developer from hassle programming overhead like user-interface design or file I/O. SAGA GIS comes with a large collection of modules, in areas of terrain-analysis, geo-statistics, image processing, and process simulation.