WordStar is a
word processor application that had a dominant market share during the early- to mid-1980s. It was published by MicroPro International, and written for the
CP/M operating system but later ported to
DOS. Although
Seymour I. Rubinstein was the principal owner of the company, Rob Barnaby was the sole author of the early versions of the program. Starting with WordStar 4.0, the program was built on new code written principally by Peter Mierau.