nomacs is an image viewer that is small, fast, and able to handle the most common image formats including RAW images. It also makes it possible to synchronize multiple viewers on a single computer or via the LAN, which is useful for comparing images and spotting the differences. This is useful for architects who want to see their progress, for example.
PHP Image Viewer is a one-file image browser and viewer for your Web site. It has a full-screen master/detail interface, with the file listing on the left side of the browser window. The image viewer area has a black background for contrast. It will display the image file selected in the left pane. After 15 seconds of idle time, the file list area will be hidden to allow more space for the image viewing area. Clicking on the image will toggle the size display from a “fit to window” mode into full-size 100% zoom mode. In full-size mode, you can use the arrow keys to scroll around the image.