Smarthistory is “a free multi-media web-book designed as a dynamic enhancement (or even substitute) for the traditional art history textbook.” It was started in 2005 by Drs. Beth Harris and Steven Zucker, who found themselves dissatisfied with traditional survey texts. They created a series of audio guides to accompany works at the Metropolitan Museum of Art and MOMA, and later supplemented these with videos, text and images for the Smarthistory website. The materials are organized chronologically, thematically, stylistically, and alphabetically by creator. It is a work in progress, and the authors hope to expand to include more non-Western content. You can read more about the background and their plans for growth here.