Please stop with this rubbish narrative - you even say later that Medley supports Common Lisp, and the Maclisp Lisp machine lineage did too. They’re all von Neumann, so not that profoundly different either.

I was not born in the days when d-machines were really alive, and also on the wrong side of the iron curtain. but I have a friend who used them quite seriously and also Genera. He does not read reddit, but I asked him. He wrote this:

Oh that’s funny: that person has never used a d-machine and has no idea what they’re talking about at all. D-machines were about as utterly different from Unixoid systems as it’s possible to be and still be a computer. I mean, really, they were just this completely alien thing that clearly had some influence from the fae in their design and working.

And the whole ‘they ran Common Lisp’: they ran Common Lisp eventually. I think Lyric had some CL but not very well, Medley had a pretty complete CL without CLOS which probably arrived later. They were essentially dead by the time they had CL.

Describing the current Interlisp thing as a ‘graft’ is pretty good. Maiko implements something that looks enough like a d-machine that sits on top of a Unix box. In the early days of it (we never used it very seriously once the hardware died as it was very expensive then and seemed like a mad waste of a perfectly good Sun) you could take a sysout from a d-machine and boot it on the emulator and it would be fine.

But actually it’s not really a graft: it’s different from that. A graft is something you do to attach an apple tree to the root system of another apple tree. But they’re both apple trees. What the Interlisp project is doing is attaching a butterfly to the root system of an apple tree or something. In such a way that the butterfly doesn’t notice it’s now part of a plant.

Genera was much less alien, but still pretty alien.