Is this a different version of GW-BASIC? The article mentions MS-DOS 4.01. Perhaps it is the version of GW-BASIC included with that? I thought a version of GW-BASIC had already been open-sourced a few years back?
Yeah, that's the version this post actually links to. I don't see any links to newer versions of GW-BASIC. It's weird, as the post title refers to GW-BASIC, but everything else is about DOS 4.xx
https://en.wikipedia.org/wiki/GW-BASIC