Will Clinger's revised (as of 19 Oct 1998) notes on the Scheme Workshop before ICFP '98 in Baltimore. Many of the subjects discussed at the workshop are now under active discussion as SRFIs.
Larceny is a simple and efficient run-time system for Scheme, currently running on the SPARC architecture. A portable implementation that generates C (dubbed "Petit Larceny") is also being developed.
Archive contains freely available technical reports and published papers, as well as PhD dissertations, written by members of the Rice Programming Languages Team.
R. Kent Dybvig's PhD dissertation (1987) which presents three implementation models for Scheme, a stack-based model, a string-based model, and a heap-based model.
A paper by Will Clinger (1991) which describes an alternative to the low-level macro facility described in the R4RS. The macrology is based upon the explicit renaming of identifiers.
A paper by Will Clinger and Jonathan Rees (1991) which describes a modified form of Kohlbecker's algorithm for reliably hygienic macro expansion in block-structured languages where macros are source-to-source transformations specified using a high-lev...
(Postscript) A paper by Matthias Blume (1997) which presents an outline of a module system for Scheme to solve several problems encountered with contemporary implementations.