William C. "Bill" Stewart (1950–August 2009) was an American computer programmer. Stewart was born in Memphis, Tennessee. He founded Stewart Software Company there in 1984 and marketed Zilog Z80 assembly language programs, notably TOOLKIT and the ONLINE 80 Bulletin Board System, for Radio Shack TRS-80 Computers running TRSDOS. Later that company became Stewart Computer & Supply, Inc. Switching to 8088 Assembly under IBM PC DOS and MS-DOS, it released many programs via shareware and commercial distribution. Bill died in August 2009 at the age of 59.