freebsd-ports/lang/moscow_ml/pkg-descr

This is Moscow ML, a lightweight implementation of Standard ML:

The current version 2.00 of Moscow ML
    * Implements Standard ML, as revised 1997 (value polymorphism, 
      default overloading resolution, new types)
    * Implements most of the new Standard ML Basis Library, including
      the most common input/output facilities in TextIO and BinIO.
    * implements separate compilation
    * can produce compact stand-alone executables (a la Caml Light)
    * supports quotations and antiquotations, useful for metaprogramming
    * includes several new libraries

WWW: http://www.dina.kvl.dk/~sestoft/mosml.html

This is a good version of the SML language if you have limited space.
If you have sufficient disk space to hold it all, the sml-nj port
- which generates native code - might be for you.