The latest commit on the Scheme repository may interest some of you.
Marc
From the Changelog:
Fixed a long standing bug with handling of keyword and rest parameters, which prevented the procedures print and println to work reliably.
Now that the print procedure is reliable and subsumes the "fringe printing" algorithm of the display procedure, the behavior of the display procedure has been changed so that it is closer to what other Scheme systems do (i.e. lists and vectors are written with parentheses, spaces, etc).