Tangent:

An (early?!) version of HN source code is available on GitHub [1]. It comes with a custom LISP dialect, ARC, that is itself running under MzScheme.

This architecture looks pretty arcane. Has anyone an idea what lead Paul, et. al. to write a custom LISP dialect for building a web forum? Is that a common thing for schemer's to do to get things done? Or does the ARC language predate the HN implementation? I am not sure.

[1] https://github.com/wting/hackernews