Summary

This document describes rationales for some of the design decisions behind the Revised⁶ Report on the Algorithmic Language Scheme. The focus is on changes made since the last revision on the report. Moreover, numerous fundamental design decisions of Scheme are also explained. This report also contains some historical notes. The formal comments submitted for drafts of the report and their responses, as archived on http://www.r6rs.org/ provides more valuable background information on many decisions that are reflected in the report.

This document frequently refers back to the Revised⁶ Report on the Algorithmic Language Scheme [28], the Revised⁶ Report on the Algorithmic Language Scheme — Libraries — [29], and the Revised⁶ Report on the Algorithmic Language Scheme — Non-Normative Appendices — [30]; specific references to the report are identified by designations such as “report section” or “report chapter”, references to the library report are identified by designations such as “library section” or “library chapter”, and references to the appendices are identified by designations such as “appendix” or “appendix section”. This document frequently refers to the whole Revised⁶ Report on the Algorithmic Language Scheme as “R⁶RS”, and to the Revised⁵ Report on the Algorithmic Language Scheme as “R⁵RS”.

This is a preliminary draft. It is intended to reflect the decisions taken by the editors’ committee, but contains many mistakes, ambiguities and inconsistencies.