XnView is a powerful image viewer and editor with multiple editing tools for professionals and casual users alike. It can read at least 400 image formats and export files to an incredible 50 different formats. You can edit ITPC metadata of an image easily through the context menu. The programs has a vast array of editing tools such as crop, rotate, adjust colors, apply effects, resize etc. It supports batch converting and renaming options for processing images on an industrial scale. It also provides support for external plugins and is an excellent alternative to any paid professional image editing software.