XnSketch
XnSketch is a free and open source program for turning photos into cartoon or sketch images
Oh My SVG
Oh My SVG is a free and open source software for convert unoptimize SVG files into smaller versions
ParaPara
ParaPara is a free and open source, lightweight image viewer with three display modes: single, spread, and continuous
YOGA Image Optimizer
YOGA Image Optimizer is a free and open source graphical tool for converting and optimizing images in JPEG, PNG and WebP format
Colorway
Colorway is a free and open source program for generate color pairings
Emulsion
Emulsion is a free and open source simple program for storing and editing palettes
Image Roll
Image Roll is a free and open source, simple and fast image viewer with basic image manipulation tools
Image Optimizer
Image Optimizer is a free and open source simple program for compressing images without loss of quality using JpegOptim and OptiPNG
Koko
Koko is a free and open source image viewer designed for desktop and touch devices
gThumb
gThumb is a free and open source program for viewing and organizing images in Linux