He, Ken Thompson and Brian Kernighan are among the set of people whose creations made modern computation possible. I throw into that list Bob Metcalfe (ethernet) and Douglas Engelbart (windowing systems and the mouse). Others came along after and made things better, smaller, faster, more integrated and more beautiful, which is all very important, but Ritchie is among those who made things possible. He will be missed.
Dennis MacAlistair Ritchie 1941-2011