Dartmouth Dante Project, founded in 1982, directed by Robert Hollander: Database containing more than 50 Dante commentaries since the times of Jacopo Alighieri. The DDP is based in Dartmouth College and was created in collaboration with Princeton University
Digital Dante, since 1992, based in the Institute for Learning Technologies, Columbia University, directed by Teodolinda Barolini and Robert O. McClintock, project manager Jennifer Hogan. Presented as "a long-term effort (...) to prototype and develop an online, multimedia Dante-related academic resource combining traditional elements of scholarly research with new communication and presentation possibilities enabled by networked digital technology". Supplies online versions of the Commedia (together with English translations) and various related texts and picture materials
ITALICA, Campus Virtuale di Lingua e Cultura Italiana, developed by RAI International together with various scholars and institutions.
See also the 'areas' Lingua italiana (courses by Francesco Bruni, Theodore J. Cachey, Mirko Tavoni) and Rinascimento (Amedeo Quondam, Claudia Cieri Via)
The World of Dante, by Deborah Parker (University of Virginia), "offers a hypermedia environment for the study of the Inferno", that is, an SGML tagged version of the Inferno with illustrations (Doré and various other sources), a search function and, if you are using a VRML-capable Web browser or a VRML plug-in, a "3D View of Dante's Inferno"