Before
Windows, before
Linux, before the
Macintosh, and when
Nintento was still dealing in
playing cards, there was
The Baby.
The Baby was the first machine ever to store not only data, but also any user program. From this starting point evolved the idea of modern computers.
Frederic Calland Williams was appointed the Chair of Electronics at the University of Manchester in 1946, and began work on a method of storing data using Cathode Ray Tubes. This would eventually become known as the Williams Tube.
When, in 1947, Williams teamed up with Tom Kilburn, their child was born a year later and it was called the Small-Scale Experimental Machine (SSEM). The two, however, soon took to calling it The Baby.
The first computer program ever stored and excecuted was designed to find factors of a very large number, and it performed its task quite well.