Watch 123Movies. World premiere of "The Demo," a music theater work written by composer/performers Mikel Rouse and Ben Neill based on Douglas Engelbart’s historic 1968 demonstration of early computer technology. Engelbart’s 1968 demo rolled out virtually everything that would define modern computing; videoconferencing, hyperlinks, networked collaboration, digital text editing, and something called a “mouse.” The Demo re-imagines Engelbart’s historic demonstration as a technologically-infused music theater piece, a new form of hybrid performance.