The JOHNNIAC or John (v. Neumann) Integrator and Automatic Computer, an early computer built by RAND, was based on the Institute for Advanced Study (IAS) architecture developed by John von Neumann and named in his honor. As with all computers of its era, it was a one of a kind machine that could not exchange programs with other computers (even other IAS machines).

JOHNNIAC operated from 1953 until February 11, 1966, logging over 50,000 operational hours.

After two "rescues" from the scrap heap, the machine currently resides at the Computer History Museum in Mountain View, California.