Drawing, graphics conversion, software development, administration.
Easy-to-use command line tool for images
Swiss army knife of image processing
Various small and useful command-line utilities
Open Source Solid Modeling CAD
Free, open-source file converter: 263 formats, offline, drag and drop
Linux fork BookScanLib.ru
Command line tool for scaling and denoising images
Complete solution for HDR photography
Convert images to Ascii Art, with a lot of options and drawing tools
smart tool for converting imageformats on command-line
angif fork with transparency layers (proof of concept implementation)
Merge image files into a single Windows icon (.ico) file.
Convert jpeg(exif/jfif)/mpo/jps image to/from xml
Converts AtariST images (.neo, .pi1, .pi2, .pi3) to gifs (using gd).