They absolutely were NOT the first to apply the term to software in general. See https://dieter.plaetinck.be/posts/open-source-undefined-part-1-the-alternative-

They absolutely were NOT the first to apply the term to software in general. See https://dieter.plaetinck.be/posts/open-source-undefined-part-1-the-alternative-origin-story/ https://dieter.plaetinck.be/posts/open-source-undefined-part... for many proven uses of "open source" being used to describe source-available software prior to the OSI's existence. As for being the first to apply the term to software licenses, yes you're correct there. But that's the inherent source of this endless confusion: they took an existing term which didn't relate to licenses, and redefined it to be entirely about licenses. It's quite ironic to say "If you want a different definition, all you have to do is invent a new term" since that's literally what the OSI failed to do! Edit to add: I would appreciate it if downvoters would cite what specific part of the linked article you disagree with, considering that it has numerous instances of irrefutable proof of "open source" being used to describe software prior to 1998, including by famous folks like Bill Joy.