[gus_massa]

From a few old post by Paul Graham, he used to run Hacker News in the REPL of Arc in the REPL of Racket. So it was posible to make tweaks on the moment, like changing the title to "Innocuous News" as a joke for a few hours. Also, he once changed the parent of one comment and created a cycle in the DAG and that cashed the site for a while. I can't find the article now.

Anyway, a few years ago dang changed the backend to SBCL that is more REPL friendly, so I guess this comment is showed using the REPL of Arc in the REPL of SBCL.

[taeric]

I think this is saying different things? The question is how much of the direct interaction is with the REPL, not if a REPL is available to use.