r4rs

from The Free On-line Dictionary of Computing (8 July 2008)

R4RS

   A revision of {R3RS}, revised in {R3.99RS}.

   (ftp://altdorf.ai.mit.edu/).

   ["The Revised^4 Report on the Algorithmic Language Scheme", W.
   Clinger et al, MIT (Nov 1991)].

   (1994-10-28)

   [Later revisions?]