Per Bothner, author of SRFI 140, Immutable Strings, has
asked me to announce "last call" for this SRFI.  He believes
that it is ready for finalization, but would like to give
reviewers one last chance to submit corrections and feedback
before we finalize it.

<https://srfi.schemers.org/srfi-140>

In particular, I appeal to anyone reading this to try the
sample implementation, run the tests, and send feedback
about your results.

If you're interested in this SRFI, please give your feedback
via the SRFI 140 mailing list before 5/17/2017.  After that,
assuming that no major revisions are required, we will
declare it final.

Regards,

SRFI Editor