- Aim for portable scripts where that isn't too hard to do, but starting
from scripts that run in a single Scheme implementation is fine.

- R5RS, R6RS, and R7RS all fair game.

- The name of the organization comes from `#! /usr/bin/env
scheme-script`. This convention has existed for a long time, but we
haven't figured out a scheme-script implementation that is useful for
writing complex, portable scripts. If the scheme-script organization
amasses a big collection of non-trivial scripts, we will have a good
body of work that shows what features are needed in a useful
`scheme-script`. A SRFI could then be written from that basis.