@techokami 'open' used to mean something else back then, it did not mean open source, but an open api. meaning everybody was able to make add-ons, extend the functionality, etc.
yes, there were systems that not even have their api's available for everybody. companies like IBM didn't even allow anybody else to create *ware that interacted/connected to their systems at all. that is where the name 'open systems' came from.