jfMagnify is a jQuery plugin that creates a magnify glass effect. This plugin will magnify html content, not just images.
ZooMove is a jQuery plugin that allows to dynamically zoom images with mouseover, and view details with mouse move.
Zoomify is a jQuery plugin for simple lightboxes with zoom effect.
MagnifierRentgen is a simple, lightweight, responsive magnifier hover plugin. (magnifying glass effect)
Simple Image Panner is a free jQuery plugin that lets you pan and zoom in on large images that are confined inside smaller containers
Zoom Slider is a simple content slider with depth-like zoom functionality.
Each slide has a predefined zoom area that will be used to calculate the appropriate scale value for a fullscreen fill. Once the icon for zooming is clicked, the zoom area as well as the page get scaled, creating the illusion that the viewer is approaching the item
zoomwall.js is a content-focused photo gallery using a horizontal masonry layout that scales up in lightbox mode.
Featured Image Zoomer lets you view a magnified portion of any image upon moving your mouse over it.
A magnifying area appears alongside the image displaying the magnified image on demand. The user can toggle the zoom level by using the mousewheel.
Zoom.js is jQuery plugin for image zoom. It's the best way to zoom an image. It transition/zooms in really cleanly..
bigpicture.js is a library that allows infinite panning and infinite zooming in HTML pages.
jQuery.imageView is a jQuery plugin that can help you to make image viewing with zoom.