During the mid-1970s Joseph Ossanna , working at Bell Laboratories , wrote the troff ( said as `` tee-roff '' ) typesetting program to drive a Wang C\/A\/T phototypesetter owned by the Labs ; it was later enhanced by Brian Kernighan to support output to different equipment such as laser printers and the like . During the mid-1970s Joseph Ossanna , working at Bell Laboratories , wrote the troff typesetting program to drive a Wang C\/A\/T phototypesetter owned by the Labs ; it was later enhanced by Brian Kernighan to support output to different equipment such as laser printers and the like .