[icebraining]

AT&T: telecommunications company that employed Dennis Ritchie and Brian Kerninghan to figure out software to play chess. Dudes created C language and UNIX OS in the process.

Much more than that, actually. From Wikipedia:

Researchers working at Bell Labs are credited with the development of radio astronomy, the transistor, the laser, the charge-coupled device (CCD), information theory, the UNIX operating system, the C programming language, S programming language and the C++ programming language. Eight Nobel Prizes have been awarded for work completed at Bell Laboratories.