Darktable - darktable is an open source photography workflow application and raw developer.
Pixlr - Pixlr® makes it easy to transform everyday images into stunning works of art.
Adobe Lightroom - Adobe Lightroom is a family of image organization and image manipulation software.
Photoscape - high quality photo editing software, that enables you to fix and enhance photos.
Pixelmator - Pixelmator is an image-editing application for Mac and iPad.
Adobe Photoshop Express - Easily edit and share your photos in no time!