[eesmith]

Thanks for the counter-example. :)

Did your company also license the code?

To explain my frame of mine, I was thinking how it was used in 2007 or later.

In the early 1990s, there wouldn't have been much off-the-shelf/free&open-source options. The GNU Scientific Library didn't start until 1996, for example (according to Wikipedia).

[Pamar]

No. I was aware of the issue at the time, and this is part of the reason for me to alter the source a bit.

In my defense, the people I was working for at the time did not even understood the topic when I talked about that.

[eesmith]

I think also that 30+ years ago software copyright was farther in the background.

The "Don't Copy that Floppy" propaganda, for example, didn't start until 1992.