WordStar 0.x/1.x

WordStar, originally from MicroPro, was a popular word processor during the early 80s. It was ported to a number of CP/M architectures as well as Unix and PC/MS-DOS. It competed directly against many word processors, including WordPerfect, Microsoft Word for DOS, and Multimate. By the late 80s most business word processing had moved to WordPerfect. In the early 90s, Microsoft Word for Windows took over.

Also see a history of WordStar: A Potted History of WordStar and some earlier 0.x versions at The WordStar Collection

Wanted: Pre-1.0 versions were sold publicly. WordStar 0.87 redump, WordStar 0.89, WordStar 0.91, WordStar 0.92, (Google results indicate these existed) WordStar 1.0. Early WordStar 2.0 releases were reported to be copy protected.