ModernView is a compact and portable image viewer.
Open the program and you'll first need to choose the pictures you'd like to browse from the single menu bar (there's support for RAW images, animated GIFs, multi-page TIFFs and more). Once this is done, they'll be displayed in thumbnail form on the left hand side, and you can move through them in various ways (cursor keys, mouse scroll wheel, clicking one directly, and so on).
Performance is excellent. You can zoom in and out, pan across an image or rotate it with a click or two, and everything moves smoothly (even with large RAW pictures).
ModernView displays basic metadata for your images, too, where it's available. The pictures can be displayed via a simple slideshow option, and there's support for multi-monitor systems, too.
Perhaps best of all, though, is the program's extreme configurability. Take just the thumbnails, for instance: you're able to set their size, aspect ratio, the number of columns they'll use, how they're sorted (by file name, size, EXIF data taken and many more), how to configure them on a multi-monitor system (thumbs on one display, full-screen image on another?), and more.
If there's a problem here it's that ModernView goes almost too far. There are so many zoom option controls, options and hotkeys, for instance, that learning exactly how everything works will take a while.
The program is versatile and packed with features, though, so if you do invest a little time in mastering the basics then it should serve you very well.
ModernView isn't always intuitive - even basic operations like zoom may not work as you'd expect - but spend a little time mastering its quirks and you'll soon have the program running smoothly