In the case of FORTRAN, there already was a language standard as early as 1966. At the same time there existed implementations of it that were independent of IB

In the case of FORTRAN, there already was a language standard as early as 1966. At the same time there existed implementations of it that were independent of IBM. Also, while you had to get a UNIX license from AT&T, they didn't make any money from it (well, they weren't allowed to) and at the time, it came with full sources. Yes, the term FOSS didn't exist yet but people shared source code anyway, at least in the academic/research environments where UNIX was popular. You're right in that things were much worse in the commercial office and home computer market.