Seymour (version:0.9.10) is a freeware image viewer with basic editing features, it is also portable.
Seymour is one of the newer entries in the image viewing world and it packs a good number of features in a lightweight download and shares similarities with XnView.
Images can be rated, categorized and tagged and a separate pane is available to view and find categorized images. Files can be grouped or filtered by filename, those tagged or not and those categorized or not and folders can be bookmarked too.
Beyond viewing many formats and moving and copying them there are basic editing features like resize, crop, rotate, grayscale, brightness, hue, auto level and format conversion to name a few. Seymour also supports scripts with some included like listing of images ready to copy into the clipboard, saving views or layouts, moving files based on properties and replacing text in file names and extensions.
One additional features is Search for images online (under Tools menu or right click the image) which uses google images to find similar images, this is in addition to the local Find similar images which will filter and display similar images in the current folder.
The program does feel sluggish at times, especially in the preview pane (see screenshot for one example of two images being overlayed after one is clicked after the other) but also the menu structure, for example List artists is under both File and Scripts menus.
Seymour is sqlite based and works on Windows XP and newer and supports touchscreen gestures.