What is wordmaster?

Some articles on wordmaster:

Seymour I. Rubinstein - Business Ventures
... totally rewrite NED into a new product, WordMaster. 1978 using Barnaby’s first two programs, WordMaster and SuperSort ... "So while WordMaster, SuperSort, and WordStar were developed on IMSAIs (I used mine til I got an IBM PC), few customers used them." -- Rob Barnaby in email to Mike Petrie 2 May 2000 ...