Moore School Lectures
Eight weeks in the summer of 1946 during which the US Army paid to teach the world how to build a stored-program computer — and thereby gave the idea away.
The course was called Theory and Techniques for Design of Electronic Digital Computers and ran from 8 July to 31 August 1946 at the Moore School of Electrical Engineering, University of Pennsylvania, the department that had just finished ENIAC. Forty-eight lectures, some thirty invited attendees from universities, government and industry in the US and Britain. The lecturers included Presper Eckert, John Mauchly, John von Neumann, Howard Aiken and George Stibitz.
Maurice Wilkes of Cambridge got his visa and his berth late and caught only the final two weeks. It was enough. Back home he built EDSAC, running in May 1949 — three years ahead of EDVAC, the machine whose design the lectures had described.
The course took place while Eckert and Mauchly were on their way out of Penn over who owned the ENIAC patents. Everything taught thus became public, and teaching a design is a remarkably poor way of keeping it a trade secret. The lectures are generally counted as the single largest reason the stored-program computer ended up common property rather than somebody's product.