> Programs compiled with it do not crash or corrupt
their memory unless there is a bug in the compiler (er, except if they
run out of stack or heap).  All types and array indices are
dynamically checked at run-time.</li>

<li><b>Portable.</b> Last time I checked, it could compile itself
successfully when compiled by Guile, MzScheme (PLT Scheme), SCM, Elk,
Gambit-C, or Chicken, although it doesn't run in Bigloo, 
Stalin, RScheme, or TinyScheme.
Retargeting it to a different processor wouldn't be a huge pain 