Seymour Ivan Rubinstein (born 1934) is a pioneer of the PC software industry. He grew up in Brooklyn, New York, and after a six-year stint in New Hampshire, later moved to California. Programs developed partially or entirely under his direction include WordStar, HelpDesk, Quattro Pro, and WebSleuth, among others. WordStar was the first truly successful program for the personal computer (in a commercial sense) and gave reasonably priced access to word processing for the general population for the first time. Rubinstein began his involvement with microcomputers as director of marketing at IMSAI.