RScheme is an object-oriented, extended version of the Scheme dialect of Lisp.
RScheme is freely redistributable, and offers reasonable performance despite
being extraordinarily portable. RScheme can be compiled to C, and the C can
then compiled with a normal C compiler to generate machine code. By default,
however, RScheme compiles to bytecodes which are interpreted by a (runtime)
virtual machine. This ensures that compilation is fast and keeps code size
down. In general, we recommend using the (default) bytecode code generation
system, and only compiling your time-critical code to machine code. This
allows a nice adjustment of space/time tradeoffs.

WWW: http://www.rscheme.org/rs/