There are three core components of the Library’s support for IIIF:
First, the Digital Repository Service (DRS) Image Delivery Service now implements the IIIF Image API. This allows any IIIF viewer to display an image or image region for the over 16,000,000 still images in the repository.
Second, the Harvard Library IIIF Presentation API service provides IIIF access to over 235,000 page turned objects from the DRS, including digitized books, manuscripts, diaries, and other digitized archival and library material.
Third, the Library has implemented Mirador as the viewer for DRS images and page turned objects. See this link, for example, to see the Harvard Library Viewer display a medieval Book of Hours from Houghton Library. The Mirador image viewer makes use of deep zoom technology via OpenSeadragon, an open-source web-based viewer for high resolution zoomable images.