showFoto - ShowFoto is the standalone image editor of the digiKam project.
Adobe Lightroom - Adobe Lightroom is a family of image organization and image manipulation software.
PixBuilder - Free Photo Editing Software for PC
Darktable - darktable is an open source photography workflow application and raw developer.
PhotoDemon - Lightweight portable BSD licensed photo editor for Windows focused on performance and usability.
Pixelmator - Pixelmator is an image-editing application for Mac and iPad.