https://github.com/informatics-isi-edu/openseadragon-viewer.git An 2D viewer based on Openseadragon for viewing zoomable tiled images in DZI and uses Annotorious for image annotation
http://openseadragon.github.io An open-source, web-based viewer for zoomable images, implemented in pure JavaScript, for desktop and mobile.
http://annotorious.github.io Image Annotation for the Web