The BBC Microcomputer System, or BBC Micro, was a series of microcomputers and associated peripherals designed and built by Acorn Computers for the BBC Computer Literacy Project, operated by the British Broadcasting Corporation. Designed with an emphasis on education, it was notable for its ruggedness, expandability and the quality of its operating system.
Following the Literacy Project's call for bids for a computer to accompany the TV programmes and literature, Acorn won the contract with the Proton, a successor to its Atom computer prototyped at short notice. Renamed the BBC Micro, the platform was adopted by most schools and became a cornerstone of computing in British education in the 1980s, changing Acorn's fortunes. It was also moderately successful as a home computer in the United Kingdom despite its high cost. Acorn directly employed the machine to simulate and develop the ARM architecture which sees widespread use in embedded systems as of 2012.
Source: Wikipedia, "BBC Micro", available under the CC-BY-SA License.