s7

s7 is a Scheme interpreter intended as an extension language for other applications. Although it is a descendant of tinyScheme, s7 is closest as a Scheme dialect to Guile 1.8. It is expected to be compatible with r5rs and r7rs. It has continuations, ratios, complex numbers, macros, keywords, hash-tables, multiprecision arithmetic, generalized `set!`, unicode, and so on. It does not have `syntax-rules` or any of its friends, and it thinks there is no such thing as an inexact integer. s7 is an extension language of Snd and sndlib, Rick Taube's Common Music (commonmusic at sourceforge), Kjetil Matheussen's Radium music editor, and Iain Duncan's Scheme for Max (or Pd).