Consisting of literally thousands of films, videos, sound files, and digitized papers, UbuWeb is a treasure trove of multi-media art. The material is presented freely for noncommercial, educational use. It is easily searchable, often has a short description, and is continually updated.
So, if you’re looking for examples of early Vito Acconci videos, recent work by Matthew Barney, the music of John Cage, or PDFs of the journal “Internationale Situationniste,” UbuWeb is a great resource to find these often esoteric works.
The site has also recently announced that all films are now available to view on mobile device.