@pluralistic UNIX was my college-age intro to all matters computer. Learning an editing & publishing process from the basic operating system built my foundation for *everything*--a foundation that hasn't often failed me since 1984/85-ish. I can't comment on most of the technicalities you're detailing, but I feel personal impact on this one. When I started out, it was proprietary and I'm really glad it didn't stay that way.