Neo (or New or Not) Simple (or Small or Suckless) X Image Viewer is a fork of
now unmaintained sxiv, the Simple X Image Viewer, with the purpose of
maintaining it and adding simple, sensible features. nsxiv is free software
licensed under GPLv2 and aims to be easy to modify and customize.

Some of its features are:

- Basic image operations, e.g. zooming, panning, rotating
- Customizable key and mouse button mappings (in config.h)
- Thumbnail mode: grid of selectable previews of all images
- Ability to cache thumbnails for fast re-loading
- Basic support for multi-frame images
- Load all frames from GIF files and play GIF animations
- Display image information in status bar

WWW: https://github.com/nsxiv/nsxiv