The term still predates OSI, but more importantly than the name than what was going on. The specific transition from sharing as public-domain software vs free,

The term still predates OSI, but more importantly than the name than what was going on. The specific transition from sharing as public-domain software vs free, open, shared, and permissivly licenced software dates to ~1953 with A-2 being provided for free and requesting updates be sent back to UNIVAC. https://en.wikipedia.org/wiki/A-0_System https://en.wikipedia.org/wiki/A-0_System Others might point to IBM SHARE from 1955 as being closer: https://en.wikipedia.org/wiki/SHARE_(computing) https://en.wikipedia.org/wiki/SHARE_(computing) Followed by many similar arrangements before the term open source was coined with OSI only showing up much later.