The GIMP is an acronym for GNU Image Manipulation Program. It is suitable for such tasks as photo retouching, image composition and image authoring. It can be used as a simple paint program, a expert quality photo retouching program, an online batch processing system, a mass production image renderer, a image format converter, etc. GIMP is extremely expandedable and extensible. It is designed to be augmented with plugins and extensions to do just about anything.

IrfanView The first graphic viewer with Multiple (animated) GIF support, one of the first graphic viewers with Multipage TIFF support and the first graphic viewer with Multiple ICO support. Features: Thumbnails, Preview, Drag and Drop Support, fast Directory View (fast moving through directory), Print Support, Scan (TWAIN) Support, Slideshow, Batch conversion, change the color depth, audio CD player, Capturing, Cut/Crop, Effects (Blur, Sharpen etc.) and many many more ... other features.
 

XnView is a utility for viewing and converting graphic files. Fatures : Import about 400 graphic file formats. Export about 40 graphic file formats. Multipage TIFF, Animated GIF, Animated ICO support. Resize, Copy/Cut/Crop Adjust brigthness, contrast... Modify number of colors, Apply filters (blur, average, emboss, ...), Apply effects (lens, wave, ...), Fullscreen mode, Slide show, Picture browser, Batch convert, Thumbnail create, Screen capture, Contact Sheet create, Multi-page file create (TIFF, DCX, LDF), TWAIN support (Windows only), Print support (Windows only), Drag and Drop support (Windows only).