How much of a "market" was there in XCMDs? As in, were they commonly exchanged or reused in any sort of open-source way, or were they written in-house? I know w

How much of a "market" was there in XCMDs? As in, were they commonly exchanged or reused in any sort of open-source way, or were they written in-house? I know we're talking about Myst specifically, but I wonder if there's any community parallel to what we see with libraries & APIs now. Although I'm just flipping over rocks looking for similarities, it's a blast to see when and how certain structures have been tried-out. Holy Smokes.. the more I read about Hypercard, the more I realize that Myst was quite a huge hack! The XCMD part is clutch. I'm curious what that community looked like, and how that code was exchanged. Beyond disks, did anyone ever host anything that looked like a repo on the early Net?