I wrote one of the first word processors for Unix, and showed it at the first UnixExpo in the Javits Center in 1984. When the company that was marketing it went out of business, I ported the word processor to the IBM PC, and it became a very popular shareware word processor (New York Word). The income from New York Word was sufficient enough that I quit my day job and formed a software company devoted to making various productivity tools.
Just curious: what did you build, with your commercial venture/startup?