In the mid to late 90s I was selling a rocketry flight computer kit:

http://www.taniwha.com/~paul/fc/index.html

We didn't have words to describe "Opensource" yet, I wrote (from the above page):

  This page is designed to be a home for the Taniwha Flight Computer which 
  I'm building and kitting for a number of other interested people. This is 
  NOT a for-profit enterprise - the idea is to get a critical mass of people 
  up and using the same hardware so that they can write cool and interesting 
  code (or make cool and interesting hardware) and share it with everyone else 
  who's using the design.

  A quick note about copyrights etc - all the stuff here is marked with my 
  copyright - this is something I do with everything I design to retain control 
  of my designs should I decide to sell them for profit in the future. However 
  everything in these pages, the design itself and the software that runs on it 
  (at least the stuff I provide) is hereby provided it for anyone's use - but I 
  retain ownership and copyright (even feel free to build them commercially if 
  you want).

You can see the gem of what later became GPL/etc there, using copyrights to retain control while releasing it to the world. Later I added:

  "Open Source" is now all the rage - we've been running this project that way
  for the past 4 years - so as always "feel free to steal anything on these web
  pages".